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Vulnerability · Published Oct 13, 2026 · Assigned by GitHub_M

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

Critical 9.1

In plain English

A critical-severity code injection in FearlessCMS from fearlessgeekmedia. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).

Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.5%top 59.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

VendorProductVersions
fearlessgeekmedia FearlessCMS < 0.1.3b

Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

References