CVE-2025-4085 Potential information leakage and privilege escalation in UITour actor

What is CVE-2025-4085?

CVE-2025-4085 is a high-severity vulnerability in Mozilla Firefox, published on 29 Apr 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

An attacker with control over a content process could potentially leverage the privileged UITour actor to leak sensitive information or escalate privileges. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

Weakness: CWE-269

Which versions are affected by CVE-2025-4085?

It affects 2 products.

Products include Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2025-4085?

Upgrade to a fixed version.

Is CVE-2025-4085 being exploited?

There is no known exploitation of CVE-2025-4085 in the wild and no public exploit code.

Other vulnerabilities in Mozilla Firefox

• CVE-2019-11708 Mozilla Firefox and Thunderbird Sandbox Escape Exploited Critical 10.0
• CVE-2010-3765 Mozilla Multiple Products Remote Code Execution Exploited Critical 9.8
• CVE-2022-26486 Mozilla Firefox Use-After-Free Exploited Critical 9.6
• CVE-2022-26485 Mozilla Firefox Use-After-Free Exploited High 8.8
• CVE-2019-11707 Mozilla Firefox and Thunderbird Type Confusion Exploited High 8.8

All Mozilla Firefox vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-8hvc-6h7p-6mcf, UBUNTU-CVE-2025-4085.