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Vulnerability record · CVE-2025-3859 · published 30 April 2025

CVE-2025-3859: Mozilla firefox focus open redirect vulnerability

Mozilla · Firefox Focus

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.

6.1 CVSS 3.1 Medium EPSS 0.20% · top 90.7% CWE-601 · Open redirectCWE-451 · CWE-451
6.1CVSS 3.1 base score
0.20%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2025-3859), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.