critical9.8
CVE-2026-4701
Use-after-free in the JavaScript Engine component.
Impact
Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mozilla | Firefox | before 140.9.0 before 149.0 |
Weakness classification
References
- NVD record
- CVE.org record
- https://bugzilla.mozilla.org/show_bug.cgi?id=2009303
- https://www.mozilla.org/security/advisories/mfsa2026-20/
- https://www.mozilla.org/security/advisories/mfsa2026-22/
- https://www.mozilla.org/security/advisories/mfsa2026-23/
- https://www.mozilla.org/security/advisories/mfsa2026-24/