CVE-2026-118021

EUVD-2026-110919
Sandbox escape due to use-after-free in the XPCOM component. This vulnerability was fixed in Firefox 159 and Thunderbird 159.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
mozillaCNA
UNKNOWN
---
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources (CNA/ADP records, vendor advisories, Enginsight analysis).
VendorProductVersionSource
mozillafirefox
𝑥
< 159
CNA
mozillathunderbird
𝑥
< 159
CNA
Debian logo
Debian Releases
Debian Product
Codename
firefox
sid
vulnerable
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/