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.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact Low

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Mozilla
  • Firefox
  • Thunderbird

Configuration 1 [-]

OR cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*

No data.

References
Link Providers
https://bugzilla.mozilla.org/show_bug.cgi?id=2025883 cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-6751 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-6751 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-30/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-30/#CVE-2026-6751 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-32/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-32/#CVE-2026-6751 cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-33/ cve-icon cve-icon
https://www.mozilla.org/security/advisories/mfsa2026-34/ cve-icon cve-icon
History

Wed, 22 Apr 2026 16:15:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla thunderbird
CPEs cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
Vendors & Products Mozilla thunderbird

Wed, 22 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-824
References
Metrics threat_severity

None

 threat_severity

Important

Wed, 22 Apr 2026 09:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-788

Wed, 22 Apr 2026 03:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-200
CWE-788

Wed, 22 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
Description Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 150 and Firefox ESR 140.10. 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.
Weaknesses CWE-457
References
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 21 Apr 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Mozilla
Mozilla firefox
Vendors & Products Mozilla
Mozilla firefox

Tue, 21 Apr 2026 13:15:00 +0000

Type Values Removed Values Added
Description Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 150 and Firefox ESR 140.10.
Title Uninitialized memory in the Audio/Video: Web Codecs component
References
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published: 2026-04-21T12:40:48.315Z

Updated: 2026-04-21T23:34:42.935Z

Reserved: 2026-04-21T12:40:47.871Z

Link: CVE-2026-6751

cve-icon Vulnrichment

Updated: 2026-04-21T18:58:22.833Z

cve-icon NVD

Status : Analyzed

Published: 2026-04-21T13:16:21.163

Modified: 2026-04-22T16:08:53.690

Link: CVE-2026-6751

cve-icon Redhat

Severity : Important

Publid Date: 2026-04-21T12:40:48Z

Links: CVE-2026-6751 - Bugzilla