CVE-2026-74956

CRITICAL CVSS 9.1 View on NVD ↗

Description

Same-origin policy bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected Products

mozilla/firefox mozilla/thunderbird

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2032406
https://www.mozilla.org/security/advisories/mfsa2026-74/
https://www.mozilla.org/security/advisories/mfsa2026-77/
https://www.mozilla.org/security/advisories/mfsa2026-78/
https://www.mozilla.org/security/advisories/mfsa2026-80/

Published: Aug 18, 2026 13:17 UTC Modified: Aug 19, 2026 01:00 UTC