VulnerabilityModified
CVE-2026-8946
This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
HIGH 7.5EPSS 0.56%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.56% probability · 45th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-119, CWE-787
- Affected
- mozilla/firefox · mozilla/thunderbird
- Source
- security@mozilla.org
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2029070Permissions 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.