🔒 Fix CVE-2025-26240: Secure HTML Meta Tag Option Parsing

[AdnanMuhib]

🔒 Fix CVE-2025-26240: Secure HTML Meta Tag Option Parsing

📝 Summary

This PR addresses the security vulnerability CVE-2025-26240 (#267) in python-pdfkit. Previously, parsing HTML meta tags with the pdfkit- prefix allowed the injection of arbitrary wkhtmltopdf options (such as --enable-local-file-access, --post-file, or --script), which could lead to Local File Inclusion (LFI) and Server-Side Request Forgery (SSRF) when rendering untrusted HTML strings.

To resolve this issue, we introduce a secure options allowlist approach that validates and filters meta options by default, while retaining full backward compatibility for trusted content through an override parameter.

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🛠️ Changes Include

• 🔒 Security Allowlist (pdfkit/security.py): Added an explicit allowlist of layout/formatting options (e.g., page-size, orientation, margins) that are safe to parse.
• 🛡️ Validation Engine (pdfkit/pdfkit.py): Updated _find_options_in_meta to filter parsed options against the allowlist and emit a RuntimeWarning when a dangerous option is blocked.
• 🔑 API Enhancement (pdfkit/api.py): Exposed the parameter allow_unsafe_meta_tags=False in from_string to give developers a secure fallback to restore legacy behavior if rendering trusted content.
• 🧪 Regression Tests (tests/pdfkit-tests.py): Added TestPDFKitSecurity to fully test default safe behavior, allowlist restrictions, parameter propagation, and warnings.
• 📝 Documentation (README.rst, HISTORY.rst): Documented the vulnerability fix, provided migration guidance, bumped package version to 2.0.1, and documented version changes.
• 🙈 Git Cleanliness (.gitignore): Added .DS_Store to git ignore rules to prevent tracking environment files.

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🧪 Test Plan

Verified that all 50 unit and integration tests pass successfully:

$ cd tests && PATH="$(pwd)/bin:$PATH" python pdfkit-tests.py
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Ran 50 tests in 0.472s

OK

[crazyse]

@AdnanMuhib I'm unsure your PR will be approved. This repository has not been maintained since years.
I'm myself patched my project and planning to switch to another maintained Python library.