Description
Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.
Affected products
mozilla: firefox; mozilla: thunderbird
References7
- www.mozilla.org/security/advisories/mfsa2026-100/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-101/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-102/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-103/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-97/ Vendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-99/ Vendor Advisory
- bugzilla.mozilla.org/show_bug.cgi?id=2068374 Permissions Required
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 24 · as of 10 November 2026
- CWE
- CWE-416
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.