CVE-2026-92048 Mozilla Firefox - Sandbox Escape

Mozilla Firefox < 156 and Firefox ESR < 153.3 contain a sandbox escape caused by incorrect boundary conditions in the Widget: Win32 component, letting attackers escape sandbox restrictions, exploit requires no special privileges.

CVSS base score 9.0 /10
Critical
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
EPSS
0.28% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Sandbox Escape
Impact
Privilege Escalation
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
Published
15 September 2026
Updated
15 October 2026
Weakness
CWE-119

Vendor fix

Update to Firefox 156 and Firefox ESR 153.3 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

← All CVEs