CVE-2026-63190
Published:October 28, 2026
Updated:November 02, 2026
FearlessCMS is a flat-file "content" management system centered on simplicity and open source. Prior to version 0.1.4, five debug/test PHP scripts under "admin/" perform privileged operations without "isLoggedIn()" authentication checks, CSRF protection or adequate "path" validation. On PHP's built-in development server, including the default Docker deployment, "router.php" checks an unnormalized admin URI prefix while the filesystem resolves dot segments, so "/./admin/" bypasses the admin login gate and executes those scripts directly. In "admin/debug_save_flow.php", attacker-controlled "path" and "content" reach "file_put_contents" for arbitrary ".md" writes under "content"/ or outside it through "path" traversal, enabling site defacement and stored JavaScript in public pages; "print_r($_POST)" output without "htmlspecialchars" escaping also causes reflected cross-site scripting. The "admin/debug_content.php" "path" parameter reaches "scandir()", "file_get_contents()" and "posix_getpwuid()", permitting arbitrary directory enumeration and ".md" file reads that expose absolute paths, ownership, permissions, hashes and "content" previews. The "admin/preview-handler.php" endpoint accepts JSON "content" and "title" and writes enumerable files under "content/_preview/", enabling stored cross-site scripting and disk exhaustion. The "admin/testdebug.php" endpoint appends to "admin/testdebug.log" without authentication, also enabling disk exhaustion. The "admin/test_redirect.php" script exposes a test artifact but escapes its inputs and is not itself an XSS sink. Stored script execution can steal sessions and compromise administrators when they view affected "content". Reads and writes execute with PHP's privileges; the tested deployment runs PHP as root, amplifying filesystem impact. This issue is fixed in version 0.1.4.
Related Resources (3)
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Contact UsCVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.4
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
LOW
Weakness Type (CWE)
Missing Authentication for Critical Functionality
Exposure of Sensitive Information to an Unauthorized Actor
Improper Limitation of a Pathname to a Restricted Directory
Authentication Bypass Using an Alternate Path or Channel
Improper Neutralization of Input During Web Page Generation
EPSS
Base Score:
0.54