CVE-2026-55695 CRITICAL

CVE-2026-55695: FearlessCMS: Remote Code Execution via Unvalidated Update Repository URL in System Updater

Vendor Fearlessgeekmedia
Product FearlessCMS
Weakness CWE-94 · Code injection
Published October 13, 2026
Last update October 13, 2026

CVSS base score

9.1/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

What the vulnerability does

01Description

FearlessCMS is a flat-file content management system centered on simplicity and open source. In 0.1.2b and earlier, an authenticated administrator can set an arbitrary Git repository URL through admin/updater-handler.php and trigger perform_update, which passes the URL to update.sh. The updater clones the repository and replaces the live plugins/, admin/, and includes/ directories without verifying the repository's identity, signatures, or contents. Because router.php permits existing PHP files under plugins to be executed by the PHP development server, attacker-supplied update content can execute arbitrary PHP with the web server process's privileges and persist as a backdoor. This issue is fixed in version 0.1.3b.

Key dates

02Disclosure timeline

October 13, 2026 CVE published

Related vulnerabilities

04Related CVE