CVE intelligence and bounded remediation

CVE-2026-54088 — File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory

Critical CVSS 9.3

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.

Severity
Critical
CVSS
9.3 (4.0)
Published
2026-06-25
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-78, CWE-88, CWE-306

Affected products

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Matched remediation archetype

Command, code, expression, and template injection

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Check exposure

  • Trace untrusted values to process execution, interpreters, evaluators, template engines, dynamic imports, and administrative scripting features.
  • Determine whether the affected path is reachable across each trust boundary and which service account or host privilege it inherits.
  • Review configuration for optional execution features, unsafe compatibility modes, and shell invocation.

Remediate safely

  • Replace string-built commands or evaluated code with fixed operations and structured argument APIs that do not invoke a shell.
  • Use strict allowlists for operation identifiers and reject unexpected input before it reaches any interpreter.
  • Update the affected component and add inert regression tests covering metacharacters, encoding variants, and alternate request paths.

Authoritative sources

Complete CVE record and remediation plan

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