CVE-2026-84117 Privilege escalation in Firefox for Android

High 8.8 Published Updated

An attacker can escalate privileges in Firefox for Android, requiring users to upgrade to the latest version.

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-2026-84117?

CVE-2026-84117 is a high-severity vulnerability in Mozilla Firefox Mobile, published on 1 Sep 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 Firefox for Android. This vulnerability was fixed in Firefox 155.

Weakness: CWE-284

Which versions are affected by CVE-2026-84117?

It affects 1 product.

Products include Mozilla Firefox Mobile.

How do I fix CVE-2026-84117?

Upgrade to a fixed version.

Is CVE-2026-84117 being exploited?

There is no known exploitation of CVE-2026-84117 in the wild and no public exploit code.

All Mozilla Firefox Mobile vulnerabilities

Sources

Also known as GHSA-j4x5-f27p-w46x, UBUNTU-CVE-2026-84117.

Is CVE-2026-84117 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free