CVE-2026-2763

Use-after-free in the JavaScript Engine component

Critical · published February 24, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
52.0
In the wild
Unconfirmed
What it is

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00685 · 52.0th percentile
Published
2026-02-24T13:33Z
EPSS history
Timeline
  • 24 FEB 13:33Z
    Use-after-free in the JavaScript Engine component
    cvelistv5