CVE-2026-6748

Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-26)

CWEs

CWE-457, CWE-824

Published

2026-04-21

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• mozilla:firefox
• mozilla:thunderbird

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=2022604
• https://www.mozilla.org/security/advisories/mfsa2026-30/
• https://www.mozilla.org/security/advisories/mfsa2026-32/
• https://www.mozilla.org/security/advisories/mfsa2026-33/
• https://www.mozilla.org/security/advisories/mfsa2026-34/

Check your stackJSON