CVE-2026-54088CWE-306CWE-78CWE-88

File Browser: Command Injection via Authentication Hook Shell Substitution (Pre-Authentication RCE)

Critical · published June 25, 2026

CVSS v4.0
9.3
EPSS
1%
Percentile
54.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
9.3 · CRITICAL
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
EPSS
0.00764 · 54.9th percentile
Weaknesses
CWE-306 · Missing Authentication for Critical Function; CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'); CWE-88 · Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
Published
2026-06-25T17:49Z
EPSS history
Timeline
  • 25 JUN 17:49Z
    File Browser: Command Injection via Authentication Hook Shell Substitution (Pre-Authentication RCE)
    cvelistv5