Description
Heap buffer overflow in libvpx. This vulnerability was fixed in Firefox 147.0.4, Firefox ESR 140.7.1, Firefox ESR 115.32.1, Thunderbird 140.7.2, and Thunderbird 147.0.2.
Published: 2026-02-16
Score: 8.8 High
EPSS: < 1% Very Low
KEV: No
Impact: Heap buffer overflow potentially enabling remote code execution
Action: Immediate Patch
AI Analysis

Impact

A vulnerable heap operation in the libvpx media decoding library allows an attacker to write beyond the intended buffer boundaries. This overflow can corrupt adjacent memory structures, leading to arbitrary code execution or a complete crash. The weakness is a classic Out‑of‑Bounds Write (CWE‑122), which can compromise confidentiality, integrity, and availability if exploited.

Affected Systems

The affected products are Mozilla Firefox and Mozilla Thunderbird. Versions prior to Firefox 147.0.4, Firefox ESR 140.7.1, Firefox ESR 115.32.1, Thunderbird 140.7.2, and Thunderbird 147.0.2 are vulnerable. All releases newer than these contain the patch.

Risk and Exploitability

The CVSS score of 8.8 classifies this vulnerability as high severity. The EPSS probability is less than 1%, indicating a low likelihood of exploitation at this time, and it is not listed in the CISA KEV catalog. The attack vector is inferred to involve a maliciously crafted VPX media file delivered through a web page or email, as libvpx is used to decode such content in browsers and mail clients.

Generated by OpenCVE AI on April 15, 2026 at 17:10 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade to the latest versions of Mozilla Firefox and Thunderbird that include the libvpx buffer overflow fix (Firefox 147.0.4, Firefox ESR 140.7.1, Firefox ESR 115.32.1, Thunderbird 140.7.2, or Thunderbird 147.0.2).
  • After applying the update, restart the affected applications to ensure the updated libvpx library is loaded.
  • Until the update can be applied, block or disable the processing of VPX‑encoded media content in browsers and mail clients, such as by blocking .vp8/.vp9 files or restricting WebP downloads from untrusted sources.

Generated by OpenCVE AI on April 15, 2026 at 17:10 UTC.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Debian DLA Debian DLA DLA-4489-1 libvpx security update
Debian DSA Debian DSA DSA-6143-1 libvpx security update
History

Mon, 13 Apr 2026 14:30:00 +0000

Type Values Removed Values Added
Description Heap buffer overflow in libvpx. This vulnerability affects Firefox < 147.0.4, Firefox ESR < 140.7.1, Firefox ESR < 115.32.1, Thunderbird < 140.7.2, and Thunderbird < 147.0.2. Heap buffer overflow in libvpx. This vulnerability was fixed in Firefox 147.0.4, Firefox ESR 140.7.1, Firefox ESR 115.32.1, Thunderbird 140.7.2, and Thunderbird 147.0.2.

Sun, 22 Feb 2026 21:30:00 +0000

Type Values Removed Values Added
References

Wed, 18 Feb 2026 21:45:00 +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:*:*:*:*:*:*:*:*
Vendors & Products Mozilla thunderbird

Wed, 18 Feb 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 threat_severity

Important

Tue, 17 Feb 2026 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-122
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

ssvc

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

Tue, 17 Feb 2026 09:00:00 +0000

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

Mon, 16 Feb 2026 15:45:00 +0000

Type Values Removed Values Added
Description Heap buffer overflow in libvpx. This vulnerability affects Firefox < 147.0.4, Firefox ESR < 140.7.1, and Firefox ESR < 115.32.1. Heap buffer overflow in libvpx. This vulnerability affects Firefox < 147.0.4, Firefox ESR < 140.7.1, Firefox ESR < 115.32.1, Thunderbird < 140.7.2, and Thunderbird < 147.0.2.
References

Mon, 16 Feb 2026 14:30:00 +0000

Type Values Removed Values Added
Description Heap buffer overflow in libvpx. This vulnerability affects Firefox < 147.0.4, Firefox ESR < 140.7.1, and Firefox ESR < 115.32.1.
Title Heap buffer overflow in libvpx
References

Subscriptions

Mozilla Firefox Firefox Esr Thunderbird
cve-icon MITRE

Status: PUBLISHED

Assigner: mozilla

Published:

Updated: 2026-04-13T13:53:57.597Z

Reserved: 2026-02-13T09:28:08.874Z

Link: CVE-2026-2447

cve-icon Vulnrichment

Updated: 2026-02-22T21:05:42.890Z

cve-icon NVD

Status : Modified

Published: 2026-02-16T15:18:34.740

Modified: 2026-04-13T15:17:19.983

Link: CVE-2026-2447

cve-icon Redhat

Severity : Important

Publid Date: 2026-02-16T14:13:23Z

Links: CVE-2026-2447 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-15T17:30:10Z

Weaknesses