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CVE-2026-0672VulnerabilityPublished Updated

CVE-2026-0672: Python Software Foundation CPython · CWE-93

Affects Python Software Foundation CPythonSource CVE Database V5

0

Not known to be exploited · CVSS 6.0 Medium · fixed in 3.15.0a6 : update Python Software Foundation CPython when convenient.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 4.0 base score
6.0Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 3.15.0a6, 3.14.3, 3.13.12 +3
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

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 20 Jan 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Python Software FoundationCPythonAffected
  • <3.10.20
  • >=3.11.0 <3.11.15
  • >=3.12.0 <3.12.13
  • >=3.13.0 <3.13.12
  • >=3.14.0 <3.14.3
  • >=3.15.0a1 <3.15.0a6
Fixed in
  • 3.15.0a6
  • 3.14.3
  • 3.13.12
  • 3.12.13
  • 3.11.15
  • 3.10.20
PyPIcpythonpkg:pypi/cpythonOther threatsAffected
  • =0
  • =3.11.0
  • =3.12.0
  • =3.13.0
  • =3.14.0
  • =3.15.0
Fixed in–
GitHubCPythonpkg:github/CPythonOther threatsAffected
  • <3.10.20
  • >=3.11.0 <3.11.15
  • >=3.12.0 <3.12.13
  • >=3.13.0 <3.13.12
  • >=3.14.0 <3.14.3
  • >=3.15.0a1 <3.15.0a6
Fixed in
  • 3.10.20
  • 3.11.15
  • 3.12.13
  • 3.13.12
  • 3.14.3
  • 3.15.0a6

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should immediately upgrade to patched CPython versions where control characters in cookie names, values, and parameters are rejected. If upgrading is not immediately feasible, implement strict input validation and sanitization on all cookie data before it reaches the http.cookies.Morsel class. Web application firewalls (WAFs) can be configured to detect and block HTTP requests containing suspicious control characters in cookies. Developers should audit their codebases for direct or indirect use of http.cookies.Morsel and ensure no untrusted input is passed without validation. Additionally, monitoring HTTP response headers for anomalies can help detect attempted exploitation. Security teams should maintain awareness of updates from the Python Software Foundation and apply security patches promptly. Finally, conduct penetration testing focused on HTTP header injection to verify the effectiveness of mitigations.

Description

When using http.cookies.Morsel, user-controlled cookie values and parameters can allow injecting HTTP headers into messages. Patch rejects all control characters within cookie names, values, and parameters.

References

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