CVE-2026-8401

Sandbox escape in the Profile Backup component

Critical · published May 12, 2026

CVSS v3.1
9.8
EPSS
1%
Percentile
47.8
In the wild
Unconfirmed
What it is

Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.

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
0.00596 · 47.8th percentile
Published
2026-05-12T14:24Z
EPSS history
Timeline
  • 12 MAY 14:24Z
    Sandbox escape in the Profile Backup component
    cvelistv5