What’s Vulnerable › Vulnerabilities

CVE-2026-25890: File Browser has a Path-Based Access Control Bypass via Multiple Leading Slashes in URL

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-02-09 · updated 2026-06-17
• Weakness: CWE-706

Description

File Browser provides a file managing interface within a specified directory and it can be used to upload, delete, preview, rename and edit files. Prior to 2.57.1, an authenticated user can bypass the application's "Disallow" file path rules by modifying the request URL. By adding multiple slashes (e.g., //private/) to the path, the authorization check fails to match the rule, while the underlying filesystem resolves the path correctly, granting unauthorized access to restricted files. This vulnerability is fixed in 2.57.1.

Affected products

• filebrowser: before 2.57.1 — fixed in 2.57.1

How to fix

Upgrade to a fixed version: filebrowser 2.57.1. Check the vendor advisory for mitigations.

References

• https://github.com/filebrowser/filebrowser/commit/489af403a19057f6b6b4b1dc0e48cbb26a202ef9
• https://github.com/filebrowser/filebrowser/releases/tag/v2.57.1
• https://github.com/filebrowser/filebrowser/security/advisories/GHSA-4mh3-h929-w968

Get alerted when CVE-2026-25890 or the next vulnerability affects your stack