Description
Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
Affected products
mozilla: firefox; mozilla: thunderbird
References8
- www.mozilla.org/security/advisories/mfsa2026-82/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-83/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-84/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-85/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-86/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-87/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-88/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=2059018 Permissions Required
Metrics
- CVSS 3.1
-
9.6
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 25 · as of 8 November 2026
- CWE
- CWE-416
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