Name: CVE-2026-8949: Integer Overflow or Wraparound
Creator: Rapid7
Published: 2026-05-19T00:00:00.000Z
License: https://www.rapid7.com/legal/website-terms-of-use/
Keywords: CVE, CVE-2026-8949, CWE-190, CVSS 7.5, EPSS 0.00583

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 Details

CVSS 3.1 Base Score: 7.5
CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Covered by Rapid7

Product	Vendor Advisory	Solution File	Added	Published
Mfsa2026 46	—	Upgrade to Mozilla Firefox version 151.0Upgrade to the latest version of Mozilla Firefox	May 19, 2026	May 19, 2026
Mfsa2026 48	—	Upgrade to Mozilla Firefox ESR version 140.11Upgrade to the latest version of Mozilla Firefox	May 19, 2026	May 19, 2026
Mozilla Thunderbird	—	Upgrade to Mozilla Thunderbird version 140.11Upgrade to the latest version of Mozilla Thunderbird	May 20, 2026	May 19, 2026
Redhat_linux	—	—	Jul 17, 2026	May 19, 2026

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CVSS Details

Covered by Rapid7

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