CVE-2026-8950

Same-origin policy bypass in the Networking: HTTP component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

Score

CVSS 3.1 9.3 Critical

Status

Analyzed - security@mozilla.org

Published

2026-05-19

Last modified

2026-10-14

Weaknesses

CWE-346

Affected products

• Firefox (Mozilla)
• Thunderbird (Mozilla)

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1965430
• https://www.mozilla.org/security/advisories/mfsa2026-46/
• https://www.mozilla.org/security/advisories/mfsa2026-48/
• https://www.mozilla.org/security/advisories/mfsa2026-50/
• https://www.mozilla.org/security/advisories/mfsa2026-51/