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CVE-2026-3644 Detail

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().


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  Python Software Foundation
CVSS-B 6.0 MEDIUM
Vector:  CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4 Python Software Foundation
https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590dd Python Software Foundation
https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979dd Python Software Foundation
https://github.com/python/cpython/issues/145599 Python Software Foundation
https://github.com/python/cpython/pull/145600 Python Software Foundation
https://mail.python.org/archives/list/[email protected]/thread/H6CADMBCDRFGWCMOXWUIHFJNV43GABJ7/ Python Software Foundation

Weakness Enumeration

CWE-ID CWE Name Source
CWE-20 Improper Input Validation CISA-ADP  
CWE-116 Improper Encoding or Escaping of Output CISA-ADP  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-3644
NVD Published Date:
03/16/2026
NVD Last Modified:
03/16/2026
Source:
Python Software Foundation