CVE-2026-74979

CVE-2026-74979

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.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-74979?
CVE-2026-74979 is a critical-severity vulnerability, classified under Improper Access Control. CVSS score: 9.8/10. Published 2026-08-18.
How severe is CVE-2026-74979?
Critical severity. CVSS v3 base score is 9.8 out of 10.