CVE-2025-23109

Name: CVE-2025-23109
Creator: NVD / NIST
Published: 2025-01-11T04:15:06.367+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.18%

Last modified Jun 17, 2026

CVE-2025-23109 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Long hostnames in URLs could be leveraged to obscure the actual host of the website or spoof the website address. This vulnerability was fixed in Firefox for iOS 134.. EPSS estimates a 0.18% chance of exploitation in the next 30 days.

Description

Long hostnames in URLs could be leveraged to obscure the actual host of the website or spoof the website address. This vulnerability was fixed in Firefox for iOS 134.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.18%

7.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-346

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 134.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1419275Issue Tracking, Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-06/Vendor Advisory

Timeline

Published: Jan 11, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-23109?

Long hostnames in URLs could be leveraged to obscure the actual host of the website or spoof the website address. This vulnerability was fixed in Firefox for iOS 134.

How severe is CVE-2025-23109?

CVE-2025-23109 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.

How do I fix CVE-2025-23109?

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-2025-23109?

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

Scan your code now

Source: NVD / NIST