Description
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.
Affected products
mozilla: firefox; mozilla: thunderbird
References8
- www.mozilla.org/security/advisories/mfsa2026-74/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-78/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=2039972 Permissions Required
- www.mozilla.org/security/advisories/mfsa2026-83/
- www.mozilla.org/security/advisories/mfsa2026-84/
- www.mozilla.org/security/advisories/mfsa2026-85/
- www.mozilla.org/security/advisories/mfsa2026-87/
- www.mozilla.org/security/advisories/mfsa2026-88/
Metrics
- CVSS 3.1
-
10.0
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 40 · as of 11 November 2026
- CWE
- CWE-693
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