CVE-2026-75874

10.0 criticalEPSS 0.5%

Critical (10.0) in mozilla. EPSS 0.5% chance of exploitation in the next 30 days.

Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154, Thunderbird 154, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 140.15, and Thunderbird 153.2.

Severity

CVSS 3.1

10.0 critical

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

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 39% of CVEs (scores of 2026-10-31)
CWE: CWE-693
Published: 2026-08-18
Modified: 2026-09-01
Record from: the NVD, synced 2026-10-19

Affected

mozilla:firefox
mozilla:thunderbird

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2039972
https://www.mozilla.org/security/advisories/mfsa2026-74/
https://www.mozilla.org/security/advisories/mfsa2026-78/
https://www.mozilla.org/security/advisories/mfsa2026-83/
https://www.mozilla.org/security/advisories/mfsa2026-84/

Check your stack JSON