High severity7.5NVD Advisory· Published May 19, 2026· Updated May 20, 2026
CVE-2026-8949
CVE-2026-8949
Description
Integer overflow in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected products
11<140.11+ 4 more
- (no CPE)range: <140.11
- cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*range: <151.0.0
- cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*range: <140.11.0
- (no CPE)range: <140.11
- (no CPE)range: <151
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*+ 2 more
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*range: <151.0.0
- cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*range: <140.11
- (no CPE)range: <151
- osv-coords3 versionspkg:rpm/opensuse/firefox-esr&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/MozillaFirefox&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/MozillaThunderbird&distro=openSUSE%20Tumbleweed
< 140.11.0-1.1+ 2 more
- (no CPE)range: < 140.11.0-1.1
- (no CPE)range: < 151.0.1-1.1
- (no CPE)range: < 140.11.1-1.1
Patches
Vulnerability mechanics
References
5- www.mozilla.org/security/advisories/mfsa2026-46/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-48/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-50/nvdVendor Advisory
- www.mozilla.org/security/advisories/mfsa2026-51/nvdVendor Advisory
- bugzilla.mozilla.org/show_bug.cginvdPermissions Required
News mentions
1- Mozilla Firefox: 25 CVEs Patched in May 2026 Update, Including Four Critical Sandbox EscapesVypr Intelligence · May 19, 2026