Vulnerability Description
Sandbox escape due to use-after-free in the XPCOM component. This vulnerability was fixed in Firefox 159 and Thunderbird 159.
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2076695
- https://www.mozilla.org/security/advisories/mfsa2026-118/
- https://www.mozilla.org/security/advisories/mfsa2026-121/
FAQ
What is CVE-2026-118021?
CVE-2026-118021 is a documented vulnerability. Sandbox escape due to use-after-free in the XPCOM component. This vulnerability was fixed in Firefox 159 and Thunderbird 159.
How severe is CVE-2026-118021?
CVSS scoring is not yet available for CVE-2026-118021. Check NVD for updates.
Is there a patch for CVE-2026-118021?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.