Vulnerability details
CVE-2026-55695
FearlessCMS: Remote Code Execution via Unvalidated Update Repository URL in System Updater
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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.1Critical | 3.1 | CVEProject cvelistV5 (CNA) (GitHub_M) | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| fearlessgeekmedia | FearlessCMS | < 0.1.3b | CVEProject cvelistV5 (CNA) |
References and advisories
4- https://github.com/fearlessgeekmedia/FearlessCMS/pull/64 x_refsource_MISC
- https://github.com/fearlessgeekmedia/FearlessCMS/commit/6dba91d496463e3940a2c917af3cae97b191de92 x_refsource_MISC
- https://github.com/fearlessgeekmedia/FearlessCMS/releases/tag/0.1.3 x_refsource_MISC
- https://github.com/fearlessgeekmedia/FearlessCMS/security/advisories/GHSA-56wm-3q3v-m93m x_refsource_CONFIRM
Details
- Published
- 2026-10-13
- Last updated
- 2026-10-13
- State
- Published
- Assigner (CNA)
- GitHub_M
- Kolun priority
- 24 · Low
Exploit prediction (EPSS)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- Proof of concept
- Technical impact
- Total
Weaknesses (CWE)
- CWE-94Improper Control of Generation of Code ('Code Injection')