CVE-2026-92071CWE-119

CVE-2026-92071

Critical · published September 15, 2026

CVSS v3.1
9.6
EPSS
0%
Percentile
14.1
In the wild
Unconfirmed
What it is

Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.

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
0.00239 · 14.1th percentile
Weakness
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer
Published
2026-09-15T17:17Z
Affected products (4)
ProductVersionsFixed in
mozilla/firefox< 153.3.0153.3.0
mozilla/firefox≥ 154.0.0, < 156.0.0156.0.0
mozilla/thunderbird< 153.3.0153.3.0
mozilla/thunderbird≥ 154.0, < 156.0156.0
References (5)
https://bugzilla.mozilla.org/show_bug.cgi?id=2061231 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-90/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-93/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-94/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-96/ · [email protected]
EPSS history
Timeline
  • 17 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 15 SEP 12:34Z
    Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component
    cvelistv5