CVE-2026-74981

Site isolation issue in the Audio/Video: Web Codecs component

State: Published
Severity: 8.1 High
Published: Aug 18, 2026
Updated: Aug 20, 2026
Reserved: Aug 17, 2026

Description

Site isolation issue in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.

Scores

CVSS	Score	Vector	Source
3.1	8.1 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N	CISA-ADP

Weaknesses

CWE-346 Origin Validation Error

Affected Products

Product	Versions
FirefoxMozilla	153.1 through 153.*Not affected 154 and laterNot affected
ThunderbirdMozilla	153.1 through 153.*Not affected 154 and laterNot affected

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2050480
https://www.mozilla.org/security/advisories/mfsa2026-74/
https://www.mozilla.org/security/advisories/mfsa2026-77/
https://www.mozilla.org/security/advisories/mfsa2026-78/
https://www.mozilla.org/security/advisories/mfsa2026-80/

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.