Nixpkgs security tracker

Untriaged

Permalink CVE-2026-3644

created 4 weeks ago

Incomplete control character validation in http.cookies

The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output().

References

https://mail.python.org/archives/list/security-announce@python.org/thread/H6CAD… vendor-advisory
https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6… patch
https://github.com/python/cpython/issues/145599 issue-tracking
https://github.com/python/cpython/pull/145600 patch
https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590… patch
https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979… patch

Affected products

CPython

<3.15.0

Matching in nixpkgs

pkgs.haskellPackages.cpython

Bindings for libpython

nixos-unstable 3.9.0
- nixpkgs-unstable 3.9.0
- nixos-unstable-small 3.9.0
nixos-25.11 3.9.0
- nixos-25.11-small 3.9.0
- nixpkgs-25.11-darwin 3.9.0

Package maintainers

@sheepforce Phillip Seeber <phillip.seeber@googlemail.com>

Suggestion detail

References

Affected products

Matching in nixpkgs

pkgs.haskellPackages.cpython

Package maintainers