CVE-2025-5020 Links using non-HTTP schemes opened from other apps such as Safari could have allowed spoofing of website addresses

What is CVE-2025-5020?

CVE-2025-5020 is a medium-severity vulnerability in Mozilla Firefox, published on 21 May 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

Opening maliciously-crafted URLs in Firefox from other apps such as Safari could have allowed attackers to spoof website addresses if the URLs utilized non-HTTP schemes used internally by the Firefox iOS client. This vulnerability was fixed in Firefox for iOS 139.

Weakness: CWE-939

Which versions are affected by CVE-2025-5020?

It affects 1 product.

Products include Mozilla Firefox.

How do I fix CVE-2025-5020?

No fix has been published for CVE-2025-5020 yet. Limit exposure of the affected software until one is available.

Is CVE-2025-5020 being exploited?

There is no known exploitation of CVE-2025-5020 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-7mfw-wgr7-m3jg.