CVE-2026-23849
File Browser provides a file managing interface within a specified directory and can be used to upload, delete, preview, rename, and edit files. Prior to version 2.55.0, the JSONAuth. Auth function contains a logic flaw that allows unauthenticated attackers to enumerate valid usernames by measuring the response time of the /api/login endpoint. The vulnerability exists due to a "short-circuit" evaluation in the authentication logic. When a username is not found in the database, the function returns immediately. However, if the username does exist, the code proceeds to verify the password using bcrypt (users.CheckPwd), which is a computationally expensive operation designed to be slow. This difference in execution path creates a measurable timing discrepancy. Version 2.55.0 contains a patch for the issue.
EPSS 0.24% · 46.8th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| github.com | filebrowser/filebrowser | 0, 0 |
| github.com | filebrowser/filebrowser/v2 | 0, 0 |
| filebrowser | filebrowser | < 2.55.0, 0, 0 |
Timeline
- Jan 19, 2026 CVE Published
- Jan 19, 2026 PoC Published
- Jan 20, 2026 EPSS Score
- Jan 21, 2026 CVE Updated
- Jan 21, 2026 PoC Published
- Jan 23, 2026 EPSS Score
- Jan 24, 2026 PoC Published
- Jan 24, 2026 PoC Published
- Jan 24, 2026 PoC Published
- Jan 24, 2026 PoC Published
- Jan 24, 2026 PoC Published
- Jan 25, 2026 EPSS Score