critical9.6
CVE-2026-8959
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component.
Impact
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Mozilla | Firefox | before 140.11.0 before 151.0.0 |
| Mozilla | Thunderbird | before 140.11 before 151.0.0 |
Weakness classification
References
- NVD record
- CVE.org record
- https://bugzilla.mozilla.org/show_bug.cgi?id=2034754
- https://www.mozilla.org/security/advisories/mfsa2026-46/
- https://www.mozilla.org/security/advisories/mfsa2026-48/
- https://www.mozilla.org/security/advisories/mfsa2026-50/
- https://www.mozilla.org/security/advisories/mfsa2026-51/