CVE-2026-124249

MEDIUMCVSS 6.3/10

Last modified

CVE-2026-124249 is a medium-severity vulnerability rated 6.3/10 on the CVSS scale. 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.

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Python Software FoundationCPython< 3.16.0

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-124249?
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.
How severe is CVE-2026-124249?
CVE-2026-124249 has a CVSS score of 6.3/10 (MEDIUM severity).
How do I fix CVE-2026-124249?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

Are you affected by CVE-2026-124249?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST