`http.cookiejar` applies expired `Set-Cookie` to cookie store before policy validation
Summary
| CVE | CVE-2026-124249 |
|---|---|
| State | PUBLISHED |
| Assigner | PSF |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-09 15:17:14 UTC |
| Updated | 2026-11-09 15:17:15 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 6.3 MEDIUM from [email protected]
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
Problem Types: CWE-346 | CWE-346 CWE-346
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.3 | MEDIUM | 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/C... |
| 4.0 | CNA | CVSS | 6.3 | MEDIUM | 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 |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
LowAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Python Software Foundation | CPython | affected 3.16.0 python | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/python/cpython/issues/161569 | [email protected] | github.com | |
| mail.python.org/archives/list/[email protected]/thread/Y6IKNZ2VZUS... | [email protected] | mail.python.org | |
| github.com/python/cpython/pull/161570 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Grant Abejar (https://github.com/vinzabe) (en)
CNA: Kirill Podoprigora (https://github.com/Eclips4) (en)
CNA: Victor Stinner (https://github.com/vstinner) (en)
There are currently no legacy QID mappings associated with this CVE.