CVE-2026-3644

Incomplete control character validation in http.cookies

Published: Mar 16, 2026Updated: Aug 13, 2026 Sources: CVE List NVD BDUCWE-20

7.5HIGH

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

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-20 CWE-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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