Security fix · CVE-2026-0672
When using http.cookies.Morsel, user-controlled cookie values and parameters can allow injecting HTTP headers into messages.
Published Jan 20, 2026 · catalog updated Mar 3, 2026 · Python Software Foundation CPython
Last checked Nov 6, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-0672. EPSS is 0.48%. Act only if a listed version of Python Software Foundation CPython is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2026-115557 · Critical
- CVE-2026-1299 · Medium
- CVE-2025-15367 · Medium
- CVE-2025-15366 · Medium
- CVE-2025-15282 · Medium
- Severity
- Medium6.0
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.48%
- Remediation
- Version ranges on file
- Affected products
- vendor Python Software Foundation CPython 3.11.0 <3.11.15
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor Python Software Foundation CPython 3.11.0 <3.11.153.11.0 <3.11.15
How to fix CVE-2026-0672
Upgrade
CVE-2026-0672 lists a fix boundary at 3.11.15. Compare the installed build with that boundary before you change production.
Version check
Seen in 3.11.0 <3.11.15
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-0672. EPSS is 0.48%. Act only if a listed version of Python Software Foundation CPython is installed.
Which versions are affected?
Compare what you have installed with Python Software Foundation CPython 3.11.0 <3.11.15 3.11.0 <3.11.15. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.48%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Jan 20, 2026 · EUVD
Detected
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.
Mar 3, 2026 · EUVD
Updated
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.
Sources
- CVE.orgVulnerability recordCVE-2026-0672
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-0672
30-day exploitation probability 0.48%
first.org - EUVDVulnerability recordEUVD-2026-3521
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.
euvd.enisa.europa.eu
References
Freshness
Last verified in this catalog Nov 6, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSNov 6, 2026
- CVE.orgNov 4, 2026
- EUVDNov 2, 2026