VulnerabilityDeferred

CVE-2026-54088

Prior to 2.63.6, the Hook Authentication feature in File Browser allows administrators to delegate login verification to an external shell command.

CRITICAL 9.3EPSS 0.76%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.76%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.76% probability · 53th percentile
CISA KEV: Not listed
Weakness: CWE-78, CWE-88, CWE-306
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.