CVE-2026-124249`http.cookiejar` applies expired `Set-Cookie` to cookie store before policy validation
- 6.3MediumCVSS base score
- 0.27%Exploitation in 30 daysEPSS · top 80% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
http.cookiejar.CookieJar deleted a stored cookie when a response carried an already expired Set-Cookie header for it, using the Domain and Path attributes from the header without consulting the cookie policy. A server could therefore delete cookies belonging to other domains from a shared cookie jar, such as the one used by urllib's HTTPCookieProcessor. The fix consults the cookie policy before an expired cookie may delete an existing one, as required by RFC 6265 section 5.3.
Timeline
ID reserved
By PSF
- 2 days later
· 2 days later
Published
- 3 days later
· 3 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| PSFCNA (assigner) | 4.0 | Medium6.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N |
| NVDNVD · Awaiting Analysis | 4.0 | Medium6.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.27% · top 80% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.3.
Affected products
Python Software Foundation · CPython
- affected < 3.16.0a2
References
References7
- https://github.com/python/cpython/pull/161570 (opens in a new tab)patch
- https://github.com/python/cpython/issues/161569 (opens in a new tab)issue-tracking
- https://mail.python.org/archives/list/[email protected]/thread/Y6IKNZ2VZUS2L6CLQICSFUEMCLT7OLTY/ (opens in a new tab)vendor-advisory
- https://github.com/python/cpython/commit/4e9d037f1cfc8e29efcb1f67bc668e06ff2b6643 (opens in a new tab)patch
- https://github.com/python/cpython/commit/8eb3d2c1c41ca7ce628554413981c1eb763a1494 (opens in a new tab)patch
- https://github.com/python/cpython/commit/ac1d49f4fbb33941475c5aa3cb663ab39d64cb73 (opens in a new tab)patch
- http://www.openwall.com/lists/oss-security/2026/11/09/24 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-120068 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-124249)Record last updated .