CVE-2026-92065 Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component

High 8.8 Published Updated
Exploited in the wild
Not known
Fix
Available

What is CVE-2026-92065?

CVE-2026-92065 is a high-severity 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-2026-92065?

It affects 2 products.

Products include Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2026-92065?

Upgrade to a fixed version.

Is CVE-2026-92065 being exploited?

There is no known exploitation of CVE-2026-92065 in the wild and no public exploit code.

All Mozilla Firefox vulnerabilities

Sources

Also known as GHSA-hmfc-frw3-6c4r, UBUNTU-CVE-2026-92065.

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