CVE-2026-92048 Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component

Critical 9.0 Published Updated
Exploited in the wild
Not known
Fix
Available

What is CVE-2026-92048?

CVE-2026-92048 is a critical vulnerability in Mozilla Firefox, published on 15 Sep 2026.

Official description

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.

Weakness: CWE-119

Which versions are affected by CVE-2026-92048?

It affects 2 products.

Products include Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2026-92048?

Upgrade to a fixed version.

Is CVE-2026-92048 being exploited?

There is no known exploitation of CVE-2026-92048 in the wild and no public exploit code.

All Mozilla Firefox vulnerabilities

Sources

Also known as GHSA-j8jw-3hwp-9q2f, UBUNTU-CVE-2026-92048.

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