CVE-2025-3859

Name: CVE-2025-3859
Creator: NVD / NIST
Published: 2025-04-30T17:15:50.903+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.17%

Last modified Jun 17, 2026

CVE-2025-3859 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage. This vulnerability was fixed in Focus 138.. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

Websites directing users to long URLs that caused eliding to occur in the location view could leverage the truncating behavior to potentially trick users into thinking they were on a different webpage. This vulnerability was fixed in Focus 138.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.17%

6.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mozilla	Firefox Focus	< 138.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1951533Issue Tracking
https://www.mozilla.org/security/advisories/mfsa2025-33/Vendor Advisory

Timeline

Published: Apr 30, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-3859?

How severe is CVE-2025-3859?

CVE-2025-3859 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.

How do I fix CVE-2025-3859?

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-2025-3859?

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

Scan your code now

Source: NVD / NIST