Vulnerability · Published Jun 25, 2026 · Assigned by GitHub_M
CVE-2026-54088File Browser: Command Injection via Authentication Hook Shell Substitution (Pre-Authentication RCE)
Critical 9.3
In plain English
A critical-severity OS command injection in filebrowser from filebrowser. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 56% 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 is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.6, the Hook Authentication feature in File Browser allows administrators to delegate login verification to an external shell command. User-supplied credentials (username and password) are interpolated into this command string using os.Expand without sanitization. An unauthenticated remote attacker can inject shell metacharacters in the username or password field at the login screen, causing the server to execute arbitrary OS commands before any authentication takes place. This is a critical pre-authentication RCE. This vulnerability is fixed in 2.63.6.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/filebrowser/filebrowser | no fix listed | GO-2026-5962 |
| Go | github.com/filebrowser/filebrowser/v2 | 2.63.6 | GO-2026-5962 |
| Go | github.com/filebrowser/filebrowser/v2 | 2.63.6 | GHSA-m93h-4hw7-5qcm |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| filebrowser | filebrowser | < 2.63.6 |
Weakness: CWE-78, CWE-88, CWE-306 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N