CVE-2026-3644

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().

More information : https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4