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CVE-2026-3644

Incomplete control character validation in http.cookies

Published: Mar 16, 2026Updated: Aug 5, 2026 Sources: CVE List NVD BDUCWE-20
7.5HIGH
NVD MITRE
EPSS Score
0.5%
Top 61.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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().

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-20CWE-116

Affected Products

Python Software Foundation
oss-project·USaka psf
CPython
OSS Libraries
python
oss-project·US
pythonLibraryLibrary
OSS Libraries
Сообщество свободного программного обеспечения
oss-projectaka fsf
Debian GNU/LinuxOn-premOS
Operating Systems / linux-distro
ООО «Ред Софт»
commercial·RUaka red soft
РЕД ОСOn-premOS
Operating Systems / linux-distro

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Initial Access
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References

https://mail.python.org/archives/list/security-announce@python.org/thread/H6CADMBCDRFGWCMOXWUIHFJNV43GABJ7/
mail.python.org
https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4
github.com
https://github.com/python/cpython/issues/145599
github.com
and 13 more references View all →

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