CVE-2026-8946

Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, 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:H/I:N/A:N

EPSS

0.6% chance of exploitation in the next 30 days; higher than 46% of CVEs (scores of 2026-10-25)

CWEs

CWE-119, CWE-787

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=2029070
• https://www.mozilla.org/security/advisories/mfsa2026-46/
• https://www.mozilla.org/security/advisories/mfsa2026-47/
• https://www.mozilla.org/security/advisories/mfsa2026-48/
• https://www.mozilla.org/security/advisories/mfsa2026-50/

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