CVE-2026-8949

Integer overflow in the Widget: Win32 component. This vulnerability was fixed in Firefox 151, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.6% chance of exploitation in the next 30 days; higher than 47% of CVEs (scores of 2026-10-25)

CWE

CWE-190

Published

2026-05-19

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• mozilla:firefox
• mozilla:thunderbird

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1355639
• 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/

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