CVE-2026-3644CWE-116CWE-20

CVE-2026-3644

High · published March 16, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
41.7
In the wild
Unconfirmed
What it is

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().

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00497 · 41.7th percentile
Weaknesses
CWE-116 · Improper Encoding or Escaping of Output; CWE-20 · Improper Input Validation
Published
2026-03-16T22:16Z
Affected products (9)
ProductVersionsFixed in
python/python< 3.13.133.13.13
python/python≥ 3.14.0, < 3.14.43.14.4
python/pythonall versions—
python/pythonall versions—
python/pythonall versions—
python/pythonall versions—
python/pythonall versions—
python/pythonall versions—
python/pythonall versions—
References (9)
https://github.com/python/cpython/commit/3974092b037f9a3b000fb15b48ea61ce3b25d330 · [email protected]https://github.com/python/cpython/commit/556aa098e738b127c714866f819b4abe2f7593d8 · [email protected]https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4 · [email protected]https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590dd · [email protected]https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979dd · [email protected]https://github.com/python/cpython/commit/dae4b1a21f8df4570e30986affd61bbe4ade4cef · [email protected]https://github.com/python/cpython/issues/145599 · [email protected]https://github.com/python/cpython/pull/145600 · [email protected]https://mail.python.org/archives/list/[email protected]/thread/H6CADMBCDRFGWCMOXWUIHFJNV43GABJ7/ · [email protected]
EPSS history
Timeline
  • 16 MAR 17:37Z
    Incomplete control character validation in http.cookies
    cvelistv5