CVE-2026-12297

Sandbox escape due to incorrect boundary conditions in the Networking component

Critical · published June 16, 2026

CVSS v3.1
9.6
EPSS
0%
Percentile
32.3
In the wild
Unconfirmed
What it is

Sandbox escape due to incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

The record
Technical detail
CVSS v3.1
9.6 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00393 · 32.3th percentile
Published
2026-06-16T11:52Z
EPSS history
Timeline
  • 16 JUN 11:52Z
    Sandbox escape due to incorrect boundary conditions in the Networking component
    cvelistv5