CVE-2026-124249

CVSS 6.3 (medium) · published 2026-11-09

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.

Weakness: CWE-346

Source: NVD CVE-2026-124249

References

• https://github.com/python/cpython/commit/4e9d037f1cfc8e29efcb1f67bc668e06ff2b6643
• https://github.com/python/cpython/commit/8eb3d2c1c41ca7ce628554413981c1eb763a1494
• https://github.com/python/cpython/commit/ac1d49f4fbb33941475c5aa3cb663ab39d64cb73
• https://github.com/python/cpython/issues/161569
• https://github.com/python/cpython/pull/161570
• https://mail.python.org/archives/list/[email protected]/thread/Y6IKNZ2VZUS2L6CLQICSFUEMCLT7OLTY/
• http://www.openwall.com/lists/oss-security/2026/11/09/24

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