CVE-2026-6748 is an uninitialized memory vulnerability in the Audio/Video: Web Codecs component affecting Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. This critical flaw allows attackers to access or manipulate sensitive data through improper memory handling in codec operations. The vulnerability carries a CVSS score of 9.8 (Critical) with a network-based attack vector requiring no user interaction or special privileges, making it highly exploitable. The attack has low complexity and impacts all three security properties: confidentiality, integrity, and availability are all rated as high. While CVE-2026-6748 is not currently listed on the Known Exploited Vulnerabilities catalog, it appears on the Active Hot List indicating community attention and heightened risk. Organizations should prioritize patching affected Firefox and Thunderbird installations, particularly those exposed to untrusted network content, given the severity rating and active monitoring status.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 140.10.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* | ||
< 150.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* | ||
< 140.10.0CPE matchmatch criteria | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.