File Browser vulnerable to Username Enumeration via Timing Attack in /api/login
Historical advisory recorded 23 Oct 2026 15:48:27 UTC. Read the latest advisory.
cve-program · CVE-2026-23849
PublishedFile 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.
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cve-program · CVE-2026-23849
PublishedFile Browser vulnerable to Username Enumeration via Timing Attack in /api/login
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.
- Source published
- 19 Jan 2026 20:37:29 UTC
- Source modified
- 20 Jan 2026 15:54:36 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
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CVSS 3.1 · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N