CVE-2026-3644
Severity CVSS v4.0:
MEDIUM
Type:
CWE-20
Input Validation
Publication date:
16/03/2026
Last modified:
17/03/2026
Description
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().
Impact
Base Score 4.0
6.00
Severity 4.0
MEDIUM
References to Advisories, Solutions, and Tools
- https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4
- https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590dd
- https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979dd
- https://github.com/python/cpython/issues/145599
- https://github.com/python/cpython/pull/145600
- https://mail.python.org/archives/list/security-announce@python.org/thread/H6CADMBCDRFGWCMOXWUIHFJNV43GABJ7/



