Vulnerability Description
Information disclosure, sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
CVSS Score
8.6
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | < 140.11.0 |
| Mozilla | Thunderbird | < 140.11 |
Related Weaknesses (CWE)
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2034713Permissions Required
- https://www.mozilla.org/security/advisories/mfsa2026-46/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-48/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-50/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2026-51/Vendor Advisory
FAQ
What is CVE-2026-8958?
CVE-2026-8958 is a vulnerability with a CVSS score of 8.6 (HIGH). Information disclosure, sandbox escape in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
How severe is CVE-2026-8958?
CVE-2026-8958 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-8958?
Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.