CVE-2026-6771

Mitigation bypass in the DOM: Security component

Critical · published April 21, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
43.7
In the wild
Unconfirmed
What it is

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.

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
0.00525 · 43.7th percentile
Published
2026-04-21T12:41Z
EPSS history
Timeline
  • 21 APR 12:41Z
    Mitigation bypass in the DOM: Security component
    cvelistv5