Vulnerability · Published Feb 9, 2026 · Assigned by GitHub_M
CVE-2026-25890File Browser has a Path-Based Access Control Bypass via Multiple Leading Slashes in URL
High 8.1
In plain English
A high-severity incorrect authorization in filebrowser from filebrowser. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/filebrowser/filebrowser | no fix listed | GO-2026-4474 |
| Go | github.com/filebrowser/filebrowser/v2 | 2.57.1 | GHSA-4mh3-h929-w968 |
| Go | github.com/filebrowser/filebrowser/v2 | 2.57.1 | GO-2026-4474 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| filebrowser | filebrowser | < 2.57.2 |
Weakness: CWE-706, CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N