CVE-2026-2771 is a critical vulnerability stemming from undefined behavior in the DOM: Core & HTML component, affecting Mozilla Firefox versions prior to 148 and 115.33 ESR, and Thunderbird versions prior to 148 and 140.8. With a CVSS score of 9.8, this vulnerability is easily exploitable over the network with low attack complexity, allowing for complete compromise of confidentiality, integrity, and availability. While there is no known active exploitation or publicly available exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered some community discussion and media coverage, indicating awareness.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 115.33.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* | ||
< 148.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* | ||
>= 128.0, < 140.8.0CPE matchmatch criteria | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* | ||
< 140.8.0CPE matchmatch criteria | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* | ||
< 148.0CPE matchmatch criteria | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* |
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.