Improper Handling of Case Sensitivity in FileBrowser - CVE-2026-25889

 

Improper Handling of Case Sensitivity in FileBrowser - CVE-2026-25889

Published: April 8, 2026


Vulnerability identifier: #VU125389
CSH Severity: Low
CVSS v4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-25889
CWE-ID: CWE-178
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote user to bypass current password verification and change a user's password.

The vulnerability exists due to improper handling of case sensitivity in the userPutHandler function in http/users.go when processing password update API requests. A remote user can send a specially crafted request using the Title Case field name "Password" to bypass current password verification and change a user's password.

The issue affects instances using the JSON authentication method, and administrators can use the same bypass to change any user's password.


Affected software

FileBrowser

How to mitigate CVE-2026-25889

Install security update from vendor's website.

FileBrowser - update to 2.57.1

External References

Related Security Bulletins