CVE-2026-2766

CWE-416 — Use After Free12 documents9 sources
Severity
9.8CRITICAL
EPSS
0.0%
top 93.88%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
3
Mozilla FirefoxMozilla Firefox ESRMozilla Thunderbird
Timeline
PublishedFeb 24

Description

Use-after-free in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 148, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitability: 3.9 | Impact: 5.9

Affected Packages7 packages

▶CVEListV5mozilla/firefoxunspecified — 148
▶NVDmozilla/firefox< 140.8.0+1
▶CVEListV5mozilla/firefox_esrunspecified — 140.8
▶CVEListV5mozilla/thunderbirdunspecified — 148+1
▶NVDmozilla/thunderbird< 140.8.0+1

🔴Vulnerability Details

3
GHSA
GHSA-59x3-pvmj-2pw2: Use-after-free in the JavaScript Engine: JIT component↗2026-02-24
▶
CVEList
Use-after-free in the JavaScript Engine: JIT component↗2026-02-24
▶
OSV
CVE-2026-2766: Use-after-free in the JavaScript Engine: JIT component↗2026-02-24
▶

📋Vendor Advisories

6
Red Hat
firefox: thunderbird: Use-after-free in the JavaScript Engine: JIT component↗2026-02-24
▶
Debian
CVE-2026-2766: firefox - Use-after-free in the JavaScript Engine: JIT component. This vulnerability affec...↗2026
▶
Mozilla
Mozilla Foundation Security Advisory 2026-13: CVE-2026-2766↗
▶
Mozilla
Mozilla Foundation Security Advisory 2026-17: CVE-2026-2766↗
▶
Mozilla
Mozilla Foundation Security Advisory 2026-15: CVE-2026-2766↗
▶

🕵️Threat Intelligence

1
Wiz
CVE-2026-2766 Impact, Exploitability, and Mitigation Steps | Wiz↗
▶

💬Community

1
Bugzilla
CVE-2026-2766 firefox: thunderbird: Use-after-free in the JavaScript Engine: JIT component↗2026-02-24
▶
CVE-2026-2766 (CRITICAL CVSS 9.8) | Use-after-free in the JavaScript En | cvebase.io