CVE-2026-92066 Sandbox escape in the Profile Backup component

Critical 9.8 Published Updated

Attackers can escape the sandbox in the Profile Backup component, potentially executing arbitrary code or escalating privileges.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-92066?

CVE-2026-92066 is a critical vulnerability in Mozilla Firefox, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.

Weakness: CWE-693

Which versions are affected by CVE-2026-92066?

It affects 2 products.

Products include Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2026-92066?

Upgrade to a fixed version.

Is CVE-2026-92066 being exploited?

There is no known exploitation of CVE-2026-92066 in the wild and no public exploit code.

All Mozilla Firefox vulnerabilities

Sources

Also known as GHSA-gx2r-3ggv-9hvj, UBUNTU-CVE-2026-92066.

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