CVE-2026-74959

CRITICAL 9.1CVE-2026-74959 · Published 18/08/2026 · updated 24/08/2026

Package	Affected versions	Patched versions
firefox mozilla	`≥ 141.0, < 153.1.0< 140.14.0`	`153.1.0140.14.0`
thunderbird mozilla	`≥ 141.0, < 153.1.0< 140.14.0`	`153.1.0140.14.0`

Description

Mitigation bypass in the Storage: Cache API component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, 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/mfsa2026-76 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-77 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-78 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-79 · Vendor Advisory
mozilla.org/security/advisories/mfsa2026-80 · Vendor Advisory

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