From 77958849468c2946496e300343c4a9fca310fd01 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 11 Jun 2026 05:30:20 +0000
Subject: [PATCH 1/8] Initial plan


From a4585d8d948ea028eb91335536458c0e5bf50727 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 11 Jun 2026 05:48:40 +0000
Subject: [PATCH 2/8] Add test documenting missing PEP249 alerts for connection
 stored in self attribute

---
 .../library-tests/frameworks/hdbcli/pep249.py | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/python/ql/test/library-tests/frameworks/hdbcli/pep249.py b/python/ql/test/library-tests/frameworks/hdbcli/pep249.py
index 713f15cb6d4f..f317a4958169 100644
--- a/python/ql/test/library-tests/frameworks/hdbcli/pep249.py
+++ b/python/ql/test/library-tests/frameworks/hdbcli/pep249.py
@@ -7,3 +7,31 @@
 cursor.executemany("some sql", (42,))  # $ getSql="some sql"
     
 cursor.close()
+
+
+# Connection stored in a class attribute (`self._conn`) and used in another method.
+#
+# This is currently NOT detected: the `Connection::instance()`/`execute()` predicates in
+# PEP249.qll are based on type tracking, which cannot follow a value that is stored into a
+# `self` attribute in one method and read from a `self` attribute in another method (see the
+# `MISSING` markers below). Regular (global) data flow handles this case correctly, so the
+# limitation is specific to the type-tracking-based modeling.
+class Database:
+    def __init__(self):
+        self._conn = dbapi.connect(address="hostname", port=300, user="username")
+
+    def get_connection(self):
+        return self._conn
+
+    def run_via_getter(self):
+        conn = self.get_connection()
+        cursor = conn.cursor()
+        cursor.execute("getter sql")  # $ MISSING: getSql="getter sql"
+
+    def run_direct(self):
+        self._conn.execute("direct sql")  # $ MISSING: getSql="direct sql"
+
+
+db = Database()
+db.run_via_getter()
+db.run_direct()

From 73bc2d70ae1067b8bc0ee0d8f55c7e9a0c38326e Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 11 Jun 2026 06:08:49 +0000
Subject: [PATCH 3/8] Model instance-attribute type flow

Use a field level step like JS and Ruby.
---
 .../new/internal/TypeTrackingImpl.qll         | 47 +++++++++++++++++++
 .../dataflow/typetracking/attribute_tests.py  |  4 +-
 .../library-tests/frameworks/hdbcli/pep249.py | 13 +++--
 3 files changed, 55 insertions(+), 9 deletions(-)

diff --git a/python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll b/python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll
index 215c7906e655..a242c1d8e50c 100644
--- a/python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll
+++ b/python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll
@@ -172,6 +172,8 @@ module TypeTrackingInput implements Shared::TypeTrackingInput<Location> {
   /** Holds if there is a level step from `nodeFrom` to `nodeTo`, which does not depend on the call graph. */
   predicate levelStepNoCall(Node nodeFrom, LocalSourceNode nodeTo) {
     TypeTrackerSummaryFlow::levelStepNoCall(nodeFrom, nodeTo)
+    or
+    localFieldStep(nodeFrom, nodeTo)
   }
 
   /**
@@ -317,6 +319,51 @@ module TypeTrackingInput implements Shared::TypeTrackingInput<Location> {
     )
   }
 
+  /**
+   * Holds if `ref` accesses attribute `attr` of `self`, where `self` is the first
+   * parameter of an instance method of `cls` (i.e. an access of the form `self.attr`).
+   *
+   * Static methods and class methods are excluded, since their first parameter is not a
+   * `self` instance reference.
+   */
+  private predicate selfAttrRef(Class cls, string attr, DataFlowPublic::AttrRef ref) {
+    exists(Function method, Name selfUse |
+      method = cls.getAMethod() and
+      not DataFlowDispatch::isStaticmethod(method) and
+      not DataFlowDispatch::isClassmethod(method) and
+      selfUse.getVariable() = method.getArg(0).(Name).getVariable() and
+      ref.getObject().asCfgNode().getNode() = selfUse and
+      ref.mayHaveAttributeName(attr)
+    )
+  }
+
+  /**
+   * Holds if `nodeFrom` is written to attribute `self.attr` in some instance method of a
+   * class, and `nodeTo` reads attribute `self.attr` in some (possibly different) instance
+   * method of the same class.
+   *
+   * This models flow through instance attributes (`self.foo`): a value stored into
+   * `self.foo` in one method can be read from `self.foo` in another method. Type-tracking
+   * handles the store and read steps via `AttrWrite`/`AttrRead`, but on its own it cannot
+   * relate the `self` of the writing method to the `self` of the reading method. Following
+   * the approach used for Ruby and JavaScript, we model this directly as a level step from
+   * the written value to the read reference, for any pair of methods on the class (not
+   * just from `__init__`).
+   *
+   * This is an over-approximation: it is instance-insensitive (it does not distinguish
+   * between different instances of the same class) and order-insensitive (it does not
+   * require the write to happen before the read), matching the precision of
+   * instance-attribute handling for Ruby and JavaScript.
+   */
+  private predicate localFieldStep(Node nodeFrom, LocalSourceNode nodeTo) {
+    exists(Class cls, string attr, DataFlowPublic::AttrWrite write, DataFlowPublic::AttrRead read |
+      selfAttrRef(cls, attr, write) and
+      nodeFrom = write.getValue() and
+      selfAttrRef(cls, attr, read) and
+      nodeTo = read
+    )
+  }
+
   /**
    * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
    */
diff --git a/python/ql/test/library-tests/dataflow/typetracking/attribute_tests.py b/python/ql/test/library-tests/dataflow/typetracking/attribute_tests.py
index c49cdf77fcdf..05496ad74d09 100644
--- a/python/ql/test/library-tests/dataflow/typetracking/attribute_tests.py
+++ b/python/ql/test/library-tests/dataflow/typetracking/attribute_tests.py
@@ -151,10 +151,10 @@ def __init__(self): # $ tracked=foo
         self.foo = tracked # $ tracked=foo tracked
 
     def print_foo(self): # $ MISSING: tracked=foo
-        print(self.foo) # $ MISSING: tracked=foo tracked
+        print(self.foo) # $ tracked MISSING: tracked=foo
 
     def possibly_uncalled_method(self): # $ MISSING: tracked=foo
-        print(self.foo) # $ MISSING: tracked=foo tracked
+        print(self.foo) # $ tracked MISSING: tracked=foo
 
 instance = MyClass2()
 print(instance.foo) # $ MISSING: tracked=foo tracked
diff --git a/python/ql/test/library-tests/frameworks/hdbcli/pep249.py b/python/ql/test/library-tests/frameworks/hdbcli/pep249.py
index f317a4958169..0c6c39086482 100644
--- a/python/ql/test/library-tests/frameworks/hdbcli/pep249.py
+++ b/python/ql/test/library-tests/frameworks/hdbcli/pep249.py
@@ -11,11 +11,10 @@
 
 # Connection stored in a class attribute (`self._conn`) and used in another method.
 #
-# This is currently NOT detected: the `Connection::instance()`/`execute()` predicates in
-# PEP249.qll are based on type tracking, which cannot follow a value that is stored into a
-# `self` attribute in one method and read from a `self` attribute in another method (see the
-# `MISSING` markers below). Regular (global) data flow handles this case correctly, so the
-# limitation is specific to the type-tracking-based modeling.
+# This is detected because type tracking includes a level step modelling flow through
+# instance attributes: a value written to `self._conn` in one method (here `__init__`) can
+# be read back from `self._conn` (directly or via a getter) in any other method on the same
+# class. This follows the same approach used for instance fields in Ruby and JavaScript.
 class Database:
     def __init__(self):
         self._conn = dbapi.connect(address="hostname", port=300, user="username")
@@ -26,10 +25,10 @@ def get_connection(self):
     def run_via_getter(self):
         conn = self.get_connection()
         cursor = conn.cursor()
-        cursor.execute("getter sql")  # $ MISSING: getSql="getter sql"
+        cursor.execute("getter sql")  # $ getSql="getter sql"
 
     def run_direct(self):
-        self._conn.execute("direct sql")  # $ MISSING: getSql="direct sql"
+        self._conn.execute("direct sql")  # $ getSql="direct sql"
 
 
 db = Database()

From befb557bfd8b0c3d1800177c155a580765abbe22 Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Thu, 11 Jun 2026 15:44:20 +0200
Subject: [PATCH 4/8] Accept fixed MISSING tests

---
 .../library-tests/CallGraph/InlineCallGraphTest.expected    | 3 ---
 .../library-tests/CallGraph/code/class_attr_assign.py       | 6 +++---
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/python/ql/test/experimental/library-tests/CallGraph/InlineCallGraphTest.expected b/python/ql/test/experimental/library-tests/CallGraph/InlineCallGraphTest.expected
index b353309e852f..1cd62c6de347 100644
--- a/python/ql/test/experimental/library-tests/CallGraph/InlineCallGraphTest.expected
+++ b/python/ql/test/experimental/library-tests/CallGraph/InlineCallGraphTest.expected
@@ -1,9 +1,6 @@
 testFailures
 debug_callableNotUnique
 pointsTo_found_typeTracker_notFound
-| code/class_attr_assign.py:10:9:10:27 | ControlFlowNode for Attribute() | my_func |
-| code/class_attr_assign.py:11:9:11:25 | ControlFlowNode for Attribute() | my_func |
-| code/class_attr_assign.py:26:9:26:25 | ControlFlowNode for Attribute() | DummyObject.method |
 | code/class_super.py:50:1:50:6 | ControlFlowNode for Attribute() | outside_def |
 | code/conditional_in_argument.py:18:5:18:11 | ControlFlowNode for Attribute() | X.bar |
 | code/func_defined_outside_class.py:21:1:21:11 | ControlFlowNode for Attribute() | A.foo |
diff --git a/python/ql/test/experimental/library-tests/CallGraph/code/class_attr_assign.py b/python/ql/test/experimental/library-tests/CallGraph/code/class_attr_assign.py
index 605375925f72..714e27dba1a0 100644
--- a/python/ql/test/experimental/library-tests/CallGraph/code/class_attr_assign.py
+++ b/python/ql/test/experimental/library-tests/CallGraph/code/class_attr_assign.py
@@ -7,8 +7,8 @@ def __init__(self, func):
         self.direct_ref = my_func
 
     def later(self):
-        self.indirect_ref() # $ pt=my_func MISSING: tt=my_func
-        self.direct_ref() # $ pt=my_func MISSING: tt=my_func
+        self.indirect_ref() # $ pt=my_func tt=my_func
+        self.direct_ref() # $ pt=my_func tt=my_func
 
 foo = Foo(my_func) # $ tt=Foo.__init__
 foo.later() # $ pt,tt=Foo.later
@@ -23,7 +23,7 @@ def __init__(self):
         self.obj = DummyObject()
 
     def later(self):
-        self.obj.method() # $ pt=DummyObject.method MISSING: tt=DummyObject.method
+        self.obj.method() # $ pt=DummyObject.method tt=DummyObject.method
 
 
 bar = Bar(my_func) # $ tt=Bar.__init__

From 913dcb119059b42918661e644333e5052f7f6a6b Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Thu, 11 Jun 2026 22:20:52 +0200
Subject: [PATCH 5/8] Add change note

---
 .../2026-06-11-fix-type-tracking-instance-attributes.md       | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 python/ql/lib/change-notes/2026-06-11-fix-type-tracking-instance-attributes.md

diff --git a/python/ql/lib/change-notes/2026-06-11-fix-type-tracking-instance-attributes.md b/python/ql/lib/change-notes/2026-06-11-fix-type-tracking-instance-attributes.md
new file mode 100644
index 000000000000..25bc0e0f31f9
--- /dev/null
+++ b/python/ql/lib/change-notes/2026-06-11-fix-type-tracking-instance-attributes.md
@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* Python type tracking now follows values stored in instance attributes such as `self.attr` across instance methods on the same class. As a result, analysis is more likely to recognize user-defined objects that are stored on `self` and used later in other methods, which may produce additional results.

From d389ea4039e28f1876b2ea962f210d3cfaecae7a Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Fri, 12 Jun 2026 13:28:00 +0100
Subject: [PATCH 6/8] Convert sql-injection test to inline expectations

---
 .../SqlInjection.expected                     | 34 +++++++++----------
 .../CWE-089-SqlInjection/SqlInjection.qlref   |  3 +-
 .../CWE-089-SqlInjection/sql_injection.py     | 10 +++---
 .../sqlalchemy_textclause.py                  | 28 +++++++--------
 4 files changed, 38 insertions(+), 37 deletions(-)

diff --git a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.expected b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.expected
index 9ff8b1d718c1..c1958c23858d 100644
--- a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.expected
+++ b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.expected
@@ -1,3 +1,20 @@
+#select
+| sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
+| sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
+| sql_injection.py:25:26:25:83 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:25:26:25:83 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
+| sql_injection.py:26:28:26:85 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:26:28:26:85 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:27:28:27:87 | ControlFlowNode for Attribute() | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:27:28:27:87 | ControlFlowNode for Attribute() | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:31:50:31:72 | ControlFlowNode for Attribute() | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:31:50:31:72 | ControlFlowNode for Attribute() | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:41:26:41:33 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:41:26:41:33 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:42:31:42:38 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:42:31:42:38 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:43:30:43:37 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:43:30:43:37 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:44:35:44:42 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:44:35:44:42 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:45:41:45:48 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:45:41:45:48 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:46:46:46:53 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:46:46:46:53 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:47:47:47:54 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:47:47:47:54 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:48:52:48:59 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:48:52:48:59 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:50:18:50:25 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:50:18:50:25 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
+| sqlalchemy_textclause.py:51:24:51:31 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:51:24:51:31 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
 edges
 | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | provenance |  |
 | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | provenance |  |
@@ -35,20 +52,3 @@ nodes
 | sqlalchemy_textclause.py:50:18:50:25 | ControlFlowNode for username | semmle.label | ControlFlowNode for username |
 | sqlalchemy_textclause.py:51:24:51:31 | ControlFlowNode for username | semmle.label | ControlFlowNode for username |
 subpaths
-#select
-| sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
-| sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
-| sql_injection.py:25:26:25:83 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:25:26:25:83 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
-| sql_injection.py:26:28:26:85 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:26:28:26:85 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:27:28:27:87 | ControlFlowNode for Attribute() | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:27:28:27:87 | ControlFlowNode for Attribute() | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:31:50:31:72 | ControlFlowNode for Attribute() | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:31:50:31:72 | ControlFlowNode for Attribute() | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:41:26:41:33 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:41:26:41:33 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:42:31:42:38 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:42:31:42:38 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:43:30:43:37 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:43:30:43:37 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:44:35:44:42 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:44:35:44:42 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:45:41:45:48 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:45:41:45:48 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:46:46:46:53 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:46:46:46:53 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:47:47:47:54 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:47:47:47:54 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:48:52:48:59 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:48:52:48:59 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:50:18:50:25 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:50:18:50:25 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
-| sqlalchemy_textclause.py:51:24:51:31 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:51:24:51:31 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
diff --git a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.qlref b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.qlref
index d1d02cbe8d37..444c0e5f46aa 100644
--- a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.qlref
+++ b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.qlref
@@ -1 +1,2 @@
-Security/CWE-089/SqlInjection.ql
+query: Security/CWE-089/SqlInjection.ql
+postprocess: utils/test/InlineExpectationsTestQuery.ql
diff --git a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/sql_injection.py b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/sql_injection.py
index c79bee16cb21..52aa3169616e 100644
--- a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/sql_injection.py
+++ b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/sql_injection.py
@@ -11,19 +11,19 @@ class User(models.Model):
     pass
 
 @app.route("/users/<username>")
-def show_user(username):
+def show_user(username): # $ Source
     with connection.cursor() as cursor:
         # GOOD -- Using parameters
         cursor.execute("SELECT * FROM users WHERE username = %s", username)
         User.objects.raw("SELECT * FROM users WHERE username = %s", (username,))
 
         # BAD -- Using string formatting
-        cursor.execute("SELECT * FROM users WHERE username = '%s'" % username)
+        cursor.execute("SELECT * FROM users WHERE username = '%s'" % username) # $ Alert
 
         # BAD -- other ways of executing raw SQL code with string interpolation
-        User.objects.annotate(RawSQL("insert into names_file ('name') values ('%s')" % username))
-        User.objects.raw("insert into names_file ('name') values ('%s')" % username)
-        User.objects.extra("insert into names_file ('name') values ('%s')" % username)
+        User.objects.annotate(RawSQL("insert into names_file ('name') values ('%s')" % username)) # $ Alert
+        User.objects.raw("insert into names_file ('name') values ('%s')" % username) # $ Alert
+        User.objects.extra("insert into names_file ('name') values ('%s')" % username) # $ Alert
 
         # BAD (but currently no custom query to find this)
         #
diff --git a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/sqlalchemy_textclause.py b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/sqlalchemy_textclause.py
index a54d64517d42..f35b1325366c 100644
--- a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/sqlalchemy_textclause.py
+++ b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/sqlalchemy_textclause.py
@@ -20,15 +20,15 @@ class User(Base):
 
 
 @app.route("/users/<username>")
-def show_user(username):
+def show_user(username): # $ Source
     session = sqlalchemy.orm.Session(engine)
 
     # BAD, normal SQL injection
-    stmt = sqlalchemy.text("SELECT * FROM users WHERE username = '{}'".format(username))
+    stmt = sqlalchemy.text("SELECT * FROM users WHERE username = '{}'".format(username)) # $ Alert
     results = session.execute(stmt).fetchall()
 
     # BAD, allows SQL injection
-    username_formatted_for_sql = sqlalchemy.text("'{}'".format(username))
+    username_formatted_for_sql = sqlalchemy.text("'{}'".format(username)) # $ Alert
     stmt = sqlalchemy.select(User).where(User.username == username_formatted_for_sql)
     results = session.execute(stmt).scalars().all()
 
@@ -38,14 +38,14 @@ def show_user(username):
 
 
     # All of these should be flagged by query
-    t1 = sqlalchemy.text(username)
-    t2 = sqlalchemy.text(text=username)
-    t3 = sqlalchemy.sql.text(username)
-    t4 = sqlalchemy.sql.text(text=username)
-    t5 = sqlalchemy.sql.expression.text(username)
-    t6 = sqlalchemy.sql.expression.text(text=username)
-    t7 = sqlalchemy.sql.expression.TextClause(username)
-    t8 = sqlalchemy.sql.expression.TextClause(text=username)
-
-    t9 = db.text(username)
-    t10 = db.text(text=username)
+    t1 = sqlalchemy.text(username) # $ Alert
+    t2 = sqlalchemy.text(text=username) # $ Alert
+    t3 = sqlalchemy.sql.text(username) # $ Alert
+    t4 = sqlalchemy.sql.text(text=username) # $ Alert
+    t5 = sqlalchemy.sql.expression.text(username) # $ Alert
+    t6 = sqlalchemy.sql.expression.text(text=username) # $ Alert
+    t7 = sqlalchemy.sql.expression.TextClause(username) # $ Alert
+    t8 = sqlalchemy.sql.expression.TextClause(text=username) # $ Alert
+
+    t9 = db.text(username) # $ Alert
+    t10 = db.text(text=username) # $ Alert

From 434a99447e087334c31a81d085ab42dcda283bb7 Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Fri, 12 Jun 2026 13:29:27 +0100
Subject: [PATCH 7/8] Add thorough tests, including one MISSING alert

---
 .../Security/CWE-089-SqlInjection/app.py      | 52 +++++++++++++++++++
 .../CWE-089-SqlInjection/db_connection.py     | 24 +++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 python/ql/test/query-tests/Security/CWE-089-SqlInjection/app.py
 create mode 100644 python/ql/test/query-tests/Security/CWE-089-SqlInjection/db_connection.py

diff --git a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/app.py b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/app.py
new file mode 100644
index 000000000000..8046f1ef52ed
--- /dev/null
+++ b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/app.py
@@ -0,0 +1,52 @@
+from fastapi import FastAPI
+from hdbcli import dbapi
+from db_connection import get_conn
+from db_connection import hdb_con
+from db_connection import hdb_con2
+from db_connection import hdb_con3
+app = FastAPI()
+
+class DatabaseConnection:
+
+    def __init__(self):
+        self._conn = dbapi.connect(address='localhost', port=30015, user='system', password='Password123')
+
+    def get_conn(self):
+        return self._conn
+
+db_connection = DatabaseConnection()
+
+@app.get("/unsafe1/")
+async def unsafe(name: str): # $ Source
+    query = "select * from users where name=" + name
+    cursor = hdb_con.cursor()
+    cursor.execute(query) # $ Alert
+    cursor.close()
+
+@app.get("/unsafe2/")
+async def unsafe2(name: str): # $ Source
+    query = "select * from users where name=" + name
+    cursor = hdb_con2.cursor()
+    cursor.execute(query) # $ Alert
+    cursor.close()
+
+@app.get("/unsafe3/")
+async def unsafe3(name: str): # $ MISSING: Source
+    query = "select * from users where name=" + name
+    cursor = hdb_con3.cursor()
+    cursor.execute(query) # $ MISSING: Alert
+    cursor.close()
+
+@app.get("/unsafe4/")
+async def unsafe4(name: str): # $ Source
+    query = "select * from users where name=" + name
+    cursor = get_conn().cursor()
+    cursor.execute(query) # $ Alert
+    cursor.close()
+
+@app.get("/unsafe5/")
+async def unsafe5(name: str): # $ Source
+    query = "select * from users where name=" + name
+    cursor = db_connection.get_conn().cursor()
+    cursor.execute(query) # $ Alert
+    cursor.close()
diff --git a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/db_connection.py b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/db_connection.py
new file mode 100644
index 000000000000..b05a43bdebba
--- /dev/null
+++ b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/db_connection.py
@@ -0,0 +1,24 @@
+from hdbcli import dbapi
+from typing import Optional
+
+hdb_con = dbapi.connect(address='localhost', port=30015, user='system', password='Password123')
+
+
+class DatabaseConnection:
+
+    def __init__(self):
+        self._conn = dbapi.connect(address='localhost', port=30015, user='system', password='Password123')
+
+    def get_conn(self):
+        return self._conn
+  
+
+hdb_con2 = DatabaseConnection().get_conn()
+hdb_con3 = DatabaseConnection()._conn
+
+_hana_connection: Optional[DatabaseConnection] = None
+def get_conn():
+    global _hana_connection
+    if _hana_connection is None:
+        _hana_connection = DatabaseConnection()
+    return _hana_connection.get_conn()

From 3bad60cf53e126d0c8ed1da7c064df7cc6d86855 Mon Sep 17 00:00:00 2001
From: Owen Mansel-Chan <owen-mc@github.com>
Date: Fri, 12 Jun 2026 13:43:24 +0100
Subject: [PATCH 8/8] Fix MISSING alert

---
 .../new/internal/TypeTrackingImpl.qll         | 40 ++++++++++++++++++-
 .../SqlInjection.expected                     | 30 ++++++++++++++
 .../Security/CWE-089-SqlInjection/app.py      |  4 +-
 3 files changed, 71 insertions(+), 3 deletions(-)

diff --git a/python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll b/python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll
index a242c1d8e50c..b76f8aeb9a57 100644
--- a/python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll
+++ b/python/ql/lib/semmle/python/dataflow/new/internal/TypeTrackingImpl.qll
@@ -167,7 +167,9 @@ module TypeTrackingInput implements Shared::TypeTrackingInput<Location> {
   }
 
   /** Holds if there is a level step from `nodeFrom` to `nodeTo`, which may depend on the call graph. */
-  predicate levelStepCall(Node nodeFrom, LocalSourceNode nodeTo) { none() }
+  predicate levelStepCall(Node nodeFrom, LocalSourceNode nodeTo) {
+    instanceFieldStep(nodeFrom, nodeTo)
+  }
 
   /** Holds if there is a level step from `nodeFrom` to `nodeTo`, which does not depend on the call graph. */
   predicate levelStepNoCall(Node nodeFrom, LocalSourceNode nodeTo) {
@@ -337,6 +339,20 @@ module TypeTrackingInput implements Shared::TypeTrackingInput<Location> {
     )
   }
 
+  /**
+   * Holds if `read` reads attribute `attr` from an instance of `cls`, where the instance
+   * is referred to from outside the methods of `cls` (i.e. an access of the form
+   * `instance.attr`, where `instance` is a reference to an instance of `cls`).
+   *
+   * This complements `selfAttrRef`, which only handles `self.attr` accesses inside the
+   * methods of `cls`. Unlike `selfAttrRef`, this depends on the call graph (via
+   * `classInstanceTracker`), so steps using it must be reported as `levelStepCall`.
+   */
+  private predicate instanceAttrRead(Class cls, string attr, DataFlowPublic::AttrRead read) {
+    read.getObject() = DataFlowDispatch::classInstanceTracker(cls) and
+    read.mayHaveAttributeName(attr)
+  }
+
   /**
    * Holds if `nodeFrom` is written to attribute `self.attr` in some instance method of a
    * class, and `nodeTo` reads attribute `self.attr` in some (possibly different) instance
@@ -364,6 +380,28 @@ module TypeTrackingInput implements Shared::TypeTrackingInput<Location> {
     )
   }
 
+  /**
+   * Holds if `nodeFrom` is written to attribute `self.attr` in some instance method of a
+   * class, and `nodeTo` reads attribute `attr` from an instance of the same class outside
+   * its methods (e.g. `instance.attr`).
+   *
+   * This is the cross-instance counterpart of `localFieldStep`: it relates a write of
+   * `self.attr` inside the class to a read of `attr` on a reference to an instance of the
+   * class. Identifying instances relies on the call graph (via `classInstanceTracker`), so
+   * this step is reported as `levelStepCall` rather than `levelStepNoCall`.
+   *
+   * Like `localFieldStep`, this is an over-approximation: it is both instance-insensitive
+   * and order-insensitive.
+   */
+  private predicate instanceFieldStep(Node nodeFrom, LocalSourceNode nodeTo) {
+    exists(Class cls, string attr, DataFlowPublic::AttrWrite write, DataFlowPublic::AttrRead read |
+      selfAttrRef(cls, attr, write) and
+      nodeFrom = write.getValue() and
+      instanceAttrRead(cls, attr, read) and
+      nodeTo = read
+    )
+  }
+
   /**
    * Holds if data can flow from `node1` to `node2` in a way that discards call contexts.
    */
diff --git a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.expected b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.expected
index c1958c23858d..8f60394d8a2b 100644
--- a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.expected
+++ b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/SqlInjection.expected
@@ -1,4 +1,9 @@
 #select
+| app.py:23:20:23:24 | ControlFlowNode for query | app.py:20:18:20:21 | ControlFlowNode for name | app.py:23:20:23:24 | ControlFlowNode for query | This SQL query depends on a $@. | app.py:20:18:20:21 | ControlFlowNode for name | user-provided value |
+| app.py:30:20:30:24 | ControlFlowNode for query | app.py:27:19:27:22 | ControlFlowNode for name | app.py:30:20:30:24 | ControlFlowNode for query | This SQL query depends on a $@. | app.py:27:19:27:22 | ControlFlowNode for name | user-provided value |
+| app.py:37:20:37:24 | ControlFlowNode for query | app.py:34:19:34:22 | ControlFlowNode for name | app.py:37:20:37:24 | ControlFlowNode for query | This SQL query depends on a $@. | app.py:34:19:34:22 | ControlFlowNode for name | user-provided value |
+| app.py:44:20:44:24 | ControlFlowNode for query | app.py:41:19:41:22 | ControlFlowNode for name | app.py:44:20:44:24 | ControlFlowNode for query | This SQL query depends on a $@. | app.py:41:19:41:22 | ControlFlowNode for name | user-provided value |
+| app.py:51:20:51:24 | ControlFlowNode for query | app.py:48:19:48:22 | ControlFlowNode for name | app.py:51:20:51:24 | ControlFlowNode for query | This SQL query depends on a $@. | app.py:48:19:48:22 | ControlFlowNode for name | user-provided value |
 | sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
 | sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
 | sql_injection.py:25:26:25:83 | ControlFlowNode for BinaryExpr | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:25:26:25:83 | ControlFlowNode for BinaryExpr | This SQL query depends on a $@. | sql_injection.py:14:15:14:22 | ControlFlowNode for username | user-provided value |
@@ -16,6 +21,16 @@
 | sqlalchemy_textclause.py:50:18:50:25 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:50:18:50:25 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
 | sqlalchemy_textclause.py:51:24:51:31 | ControlFlowNode for username | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:51:24:51:31 | ControlFlowNode for username | This SQL query depends on a $@. | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | user-provided value |
 edges
+| app.py:20:18:20:21 | ControlFlowNode for name | app.py:21:5:21:9 | ControlFlowNode for query | provenance |  |
+| app.py:21:5:21:9 | ControlFlowNode for query | app.py:23:20:23:24 | ControlFlowNode for query | provenance |  |
+| app.py:27:19:27:22 | ControlFlowNode for name | app.py:28:5:28:9 | ControlFlowNode for query | provenance |  |
+| app.py:28:5:28:9 | ControlFlowNode for query | app.py:30:20:30:24 | ControlFlowNode for query | provenance |  |
+| app.py:34:19:34:22 | ControlFlowNode for name | app.py:35:5:35:9 | ControlFlowNode for query | provenance |  |
+| app.py:35:5:35:9 | ControlFlowNode for query | app.py:37:20:37:24 | ControlFlowNode for query | provenance |  |
+| app.py:41:19:41:22 | ControlFlowNode for name | app.py:42:5:42:9 | ControlFlowNode for query | provenance |  |
+| app.py:42:5:42:9 | ControlFlowNode for query | app.py:44:20:44:24 | ControlFlowNode for query | provenance |  |
+| app.py:48:19:48:22 | ControlFlowNode for name | app.py:49:5:49:9 | ControlFlowNode for query | provenance |  |
+| app.py:49:5:49:9 | ControlFlowNode for query | app.py:51:20:51:24 | ControlFlowNode for query | provenance |  |
 | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | provenance |  |
 | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | provenance |  |
 | sql_injection.py:14:15:14:22 | ControlFlowNode for username | sql_injection.py:25:26:25:83 | ControlFlowNode for BinaryExpr | provenance |  |
@@ -33,6 +48,21 @@ edges
 | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:50:18:50:25 | ControlFlowNode for username | provenance |  |
 | sqlalchemy_textclause.py:23:15:23:22 | ControlFlowNode for username | sqlalchemy_textclause.py:51:24:51:31 | ControlFlowNode for username | provenance |  |
 nodes
+| app.py:20:18:20:21 | ControlFlowNode for name | semmle.label | ControlFlowNode for name |
+| app.py:21:5:21:9 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:23:20:23:24 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:27:19:27:22 | ControlFlowNode for name | semmle.label | ControlFlowNode for name |
+| app.py:28:5:28:9 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:30:20:30:24 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:34:19:34:22 | ControlFlowNode for name | semmle.label | ControlFlowNode for name |
+| app.py:35:5:35:9 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:37:20:37:24 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:41:19:41:22 | ControlFlowNode for name | semmle.label | ControlFlowNode for name |
+| app.py:42:5:42:9 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:44:20:44:24 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:48:19:48:22 | ControlFlowNode for name | semmle.label | ControlFlowNode for name |
+| app.py:49:5:49:9 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
+| app.py:51:20:51:24 | ControlFlowNode for query | semmle.label | ControlFlowNode for query |
 | sql_injection.py:14:15:14:22 | ControlFlowNode for username | semmle.label | ControlFlowNode for username |
 | sql_injection.py:21:24:21:77 | ControlFlowNode for BinaryExpr | semmle.label | ControlFlowNode for BinaryExpr |
 | sql_injection.py:24:38:24:95 | ControlFlowNode for BinaryExpr | semmle.label | ControlFlowNode for BinaryExpr |
diff --git a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/app.py b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/app.py
index 8046f1ef52ed..4de61346d8f5 100644
--- a/python/ql/test/query-tests/Security/CWE-089-SqlInjection/app.py
+++ b/python/ql/test/query-tests/Security/CWE-089-SqlInjection/app.py
@@ -31,10 +31,10 @@ async def unsafe2(name: str): # $ Source
     cursor.close()
 
 @app.get("/unsafe3/")
-async def unsafe3(name: str): # $ MISSING: Source
+async def unsafe3(name: str): # $ Source
     query = "select * from users where name=" + name
     cursor = hdb_con3.cursor()
-    cursor.execute(query) # $ MISSING: Alert
+    cursor.execute(query) # $ Alert
     cursor.close()
 
 @app.get("/unsafe4/")