CVE-2025-5020

Name: CVE-2025-5020
Creator: NVD / NIST
Published: 2025-05-21T18:15:53.84+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.20%

Last modified Jun 17, 2026

CVE-2025-5020 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. 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.. EPSS estimates a 0.20% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

EPSS Probability

0.20%

9.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-939

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 139.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1951558Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-39/Vendor Advisory

Timeline

Published: May 21, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-5020?

How severe is CVE-2025-5020?

CVE-2025-5020 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.20% probability of exploitation in the next 30 days.

How do I fix CVE-2025-5020?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-5020?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST