Auth bypass in Filebrowser
CVE-2026-25890
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.006 (44.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001
Affected products
- Filebrowser — versions < 2.57.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/filebrowser/filebrowser/security/advisories/GHSA-4mh3-h929-w968 (Exploit, Vendor Advisory)
- github.com/filebrowser/filebrowser/commit/489af403a19057f6b6b4b1dc0e48cbb26a202… (Patch)
- github.com/filebrowser/filebrowser/releases/tag/v2.57.1 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-25890?
- CVE-2026-25890 is a high-severity vulnerability in Filebrowser, classified under Use of Incorrectly-Resolved Name or Reference. CVSS score: 8.1/10. Published 2026-02-09.
- How severe is CVE-2026-25890?
- High severity. CVSS v3 base score is 8.1 out of 10.
- Is CVE-2026-25890 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.