CVE-2025-1019 Fullscreen notification not properly displayed

Medium 4.3 Published Updated

Attackers can manipulate window z-order to hide fullscreen notifications, enabling spoofing attacks in Firefox and Thunderbird.

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-2025-1019?

CVE-2025-1019 is a medium-severity vulnerability in Mozilla Firefox, published on 4 Feb 2025. 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

The z-order of the browser windows could be manipulated to hide the fullscreen notification. This could potentially be leveraged to perform a spoofing attack. This vulnerability was fixed in Firefox 135 and Thunderbird 135.

Weakness: CWE-1021

Which versions are affected by CVE-2025-1019?

It affects 2 products.

Products include Mozilla Firefox, Mozilla Thunderbird.

How do I fix CVE-2025-1019?

Upgrade to a fixed version.

Is CVE-2025-1019 being exploited?

There is no known exploitation of CVE-2025-1019 in the wild and no public exploit code.

All Mozilla Firefox vulnerabilities

Sources

Also known as GHSA-gg39-4c5c-pfx2, UBUNTU-CVE-2025-1019.

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