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.
References
Link Resource
https://bugzilla.mozilla.org/show_bug.cgi?id=2029070 Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-46/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-47/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-48/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-50/ Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-51/ Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:21378
https://access.redhat.com/errata/RHSA-2026:21380
https://access.redhat.com/errata/RHSA-2026:21381
https://access.redhat.com/errata/RHSA-2026:21382
https://access.redhat.com/errata/RHSA-2026:22325
https://access.redhat.com/errata/RHSA-2026:22643
https://access.redhat.com/errata/RHSA-2026:26174
https://access.redhat.com/errata/RHSA-2026:26268
https://access.redhat.com/errata/RHSA-2026:26269
https://access.redhat.com/errata/RHSA-2026:26270
https://access.redhat.com/errata/RHSA-2026:26491
https://access.redhat.com/errata/RHSA-2026:26492
https://access.redhat.com/errata/RHSA-2026:26493
https://access.redhat.com/errata/RHSA-2026:26521
https://access.redhat.com/errata/RHSA-2026:26536
https://access.redhat.com/errata/RHSA-2026:26539
https://access.redhat.com/errata/RHSA-2026:26551
https://access.redhat.com/errata/RHSA-2026:26606
https://access.redhat.com/errata/RHSA-2026:26629
https://access.redhat.com/errata/RHSA-2026:26630
https://access.redhat.com/errata/RHSA-2026:27715
https://access.redhat.com/security/cve/CVE-2026-8946
https://bugzilla.redhat.com/show_bug.cgi?id=2479849
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8946.json
Configurations

Configuration 1 (hide)

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

History

15 Jul 2026, 12:18

Type Values Removed Values Added
CWE CWE-787
References
  • () https://access.redhat.com/errata/RHSA-2026:21378 -
  • () https://access.redhat.com/errata/RHSA-2026:21380 -
  • () https://access.redhat.com/errata/RHSA-2026:21381 -
  • () https://access.redhat.com/errata/RHSA-2026:21382 -
  • () https://access.redhat.com/errata/RHSA-2026:22325 -
  • () https://access.redhat.com/errata/RHSA-2026:22643 -
  • () https://access.redhat.com/errata/RHSA-2026:26174 -
  • () https://access.redhat.com/errata/RHSA-2026:26268 -
  • () https://access.redhat.com/errata/RHSA-2026:26269 -
  • () https://access.redhat.com/errata/RHSA-2026:26270 -
  • () https://access.redhat.com/errata/RHSA-2026:26491 -
  • () https://access.redhat.com/errata/RHSA-2026:26492 -
  • () https://access.redhat.com/errata/RHSA-2026:26493 -
  • () https://access.redhat.com/errata/RHSA-2026:26521 -
  • () https://access.redhat.com/errata/RHSA-2026:26536 -
  • () https://access.redhat.com/errata/RHSA-2026:26539 -
  • () https://access.redhat.com/errata/RHSA-2026:26551 -
  • () https://access.redhat.com/errata/RHSA-2026:26606 -
  • () https://access.redhat.com/errata/RHSA-2026:26629 -
  • () https://access.redhat.com/errata/RHSA-2026:26630 -
  • () https://access.redhat.com/errata/RHSA-2026:27715 -
  • () https://access.redhat.com/security/cve/CVE-2026-8946 -
  • () https://bugzilla.redhat.com/show_bug.cgi?id=2479849 -
  • () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8946.json -

15 Jul 2026, 03:16

Type Values Removed Values Added
References
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:21378', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:21380', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:21381', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:21382', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:22325', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:22643', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26174', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26268', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26269', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26270', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26491', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26492', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26493', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26521', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26536', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26539', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26551', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26606', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26629', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:26630', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/errata/RHSA-2026:27715', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://access.redhat.com/security/cve/CVE-2026-8946', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://bugzilla.redhat.com/show_bug.cgi?id=2479849', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
  • {'url': 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8946.json', 'source': '0b0ca135-0b70-47e7-9f44-1890c2a1c46c'}
CWE CWE-787

30 Jun 2026, 03:21

Type Values Removed Values Added
References
  • () https://access.redhat.com/errata/RHSA-2026:21378 -
  • () https://access.redhat.com/errata/RHSA-2026:21380 -
  • () https://access.redhat.com/errata/RHSA-2026:21381 -
  • () https://access.redhat.com/errata/RHSA-2026:21382 -
  • () https://access.redhat.com/errata/RHSA-2026:22325 -
  • () https://access.redhat.com/errata/RHSA-2026:22643 -
  • () https://access.redhat.com/errata/RHSA-2026:26174 -
  • () https://access.redhat.com/errata/RHSA-2026:26268 -
  • () https://access.redhat.com/errata/RHSA-2026:26269 -
  • () https://access.redhat.com/errata/RHSA-2026:26270 -
  • () https://access.redhat.com/errata/RHSA-2026:26491 -
  • () https://access.redhat.com/errata/RHSA-2026:26492 -
  • () https://access.redhat.com/errata/RHSA-2026:26493 -
  • () https://access.redhat.com/errata/RHSA-2026:26521 -
  • () https://access.redhat.com/errata/RHSA-2026:26536 -
  • () https://access.redhat.com/errata/RHSA-2026:26539 -
  • () https://access.redhat.com/errata/RHSA-2026:26551 -
  • () https://access.redhat.com/errata/RHSA-2026:26606 -
  • () https://access.redhat.com/errata/RHSA-2026:26629 -
  • () https://access.redhat.com/errata/RHSA-2026:26630 -
  • () https://access.redhat.com/errata/RHSA-2026:27715 -
  • () https://access.redhat.com/security/cve/CVE-2026-8946 -
  • () https://bugzilla.redhat.com/show_bug.cgi?id=2479849 -
  • () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-8946.json -
CWE CWE-787

19 May 2026, 18:50

Type Values Removed Values Added
References () https://bugzilla.mozilla.org/show_bug.cgi?id=2029070 - () https://bugzilla.mozilla.org/show_bug.cgi?id=2029070 - Permissions Required
References () https://www.mozilla.org/security/advisories/mfsa2026-46/ - () https://www.mozilla.org/security/advisories/mfsa2026-46/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-47/ - () https://www.mozilla.org/security/advisories/mfsa2026-47/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-48/ - () https://www.mozilla.org/security/advisories/mfsa2026-48/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-50/ - () https://www.mozilla.org/security/advisories/mfsa2026-50/ - Vendor Advisory
References () https://www.mozilla.org/security/advisories/mfsa2026-51/ - () https://www.mozilla.org/security/advisories/mfsa2026-51/ - Vendor Advisory
CPE cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
First Time Mozilla thunderbird
Mozilla
Mozilla firefox

19 May 2026, 18:16

Type Values Removed Values Added
References
  • () https://www.mozilla.org/security/advisories/mfsa2026-50/ -
  • () https://www.mozilla.org/security/advisories/mfsa2026-51/ -
Summary (en) Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, and Firefox ESR 140.11. (en) 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.

19 May 2026, 15:16

Type Values Removed Values Added
CWE CWE-119
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.5

19 May 2026, 14:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-05-19 14:16

Updated : 2026-07-15 12:18


NVD link : CVE-2026-8946

Mitre link : CVE-2026-8946

CVE.ORG link : CVE-2026-8946


JSON object : View

Products Affected

mozilla

  • firefox
  • thunderbird
CWE
CWE-119

Improper Restriction of Operations within the Bounds of a Memory Buffer

CWE-787

Out-of-bounds Write