CVE-2026-4686 is a high-severity vulnerability (CVSS 7.5) caused by incorrect boundary conditions in the Graphics: Canvas2D component of Mozilla Firefox and Thunderbird, affecting specific versions prior to 149, 140.9, and Firefox ESR prior to 115.34 and 140.9. This flaw can be exploited remotely over the network with low attack complexity and no user interaction, primarily leading to a high impact on system availability (Denial of Service). There is currently no evidence of active exploitation, nor are public exploit codes available in common repositories like Metasploit or ExploitDB. Community discussion and media coverage are minimal, limited to vendor security advisories.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 115.34.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* | ||
< 149.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* | ||
>= 128.0, < 140.9.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.