CVE-2026-74979

CRITICAL 9.8CVE-2026-74979 · Published 18/08/2026 · updated 20/08/2026

Package	Affected versions	Patched versions
firefox mozilla	`< 153.1.0< 154.0.0`	`153.1.0154.0.0`
thunderbird mozilla	`< 153.1.0< 154.0`	`153.1.0154.0`

Description

Mitigation bypass in the Add-ons Manager component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

References

bugzilla.mozilla.org/show_bug.cgi · Permissions Required
mozilla.org/security/advisories/mfsa2026-74 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-77 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-78 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-80 · Vendor Advisory

Running one of these products? Scan your site to see whether it exposes a vulnerable version.

Scan my site free