CVE-2026-8952 Privilege escalation in the Application Update component

High 8.8 Published Updated

Attackers can escalate privileges via the Application Update component in Firefox and Thunderbird, requiring an upgrade to version 151.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2026-8952?

CVE-2026-8952 is a high-severity vulnerability in Mozilla Firefox, published on 19 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Privilege escalation in the Application Update component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

Weakness: CWE-269

Which versions are affected by CVE-2026-8952?

It affects 2 products.

Products include Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2026-8952?

Upgrade to a fixed version.

Is CVE-2026-8952 being exploited?

There is no known exploitation of CVE-2026-8952 in the wild and no public exploit code.

All Mozilla Firefox vulnerabilities

Sources

Also known as GHSA-hrqc-vwff-62mj, UBUNTU-CVE-2026-8952.

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