---
id: CVE-2026-63190
title: >-
  FearlessCMS: Unauthenticated debug scripts expose filesystem operations and
  XSS
summary: >-
  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,…
severity: critical
cvss: 9.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L'
cvssSource: cna
cwe:
  - CWE-306
  - CWE-288
  - CWE-22
  - CWE-79
  - CWE-200
vendor: fearlessgeekmedia
product: FearlessCMS
affected:
  - FearlessCMS < 0.1.4
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-29T18:35:27.307607Z'
exploitAvailable: true
published: '2026-10-28'
updated: '2026-10-29'
sourceUpdated: '2026-10-29T18:35:51.109Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-63190'
references:
  - url: >-
      https://github.com/fearlessgeekmedia/FearlessCMS/security/advisories/GHSA-3mq8-hrhf-7hv6
    label: >-
      https://github.com/fearlessgeekmedia/FearlessCMS/security/advisories/GHSA-3mq8-hrhf-7hv6
  - url: >-
      https://github.com/fearlessgeekmedia/FearlessCMS/commit/59fb22cf989b5ba14c387c3212e15b146e02cf9a
    label: >-
      https://github.com/fearlessgeekmedia/FearlessCMS/commit/59fb22cf989b5ba14c387c3212e15b146e02cf9a
  - url: 'https://github.com/fearlessgeekmedia/FearlessCMS/tree/0.1.4'
    label: 'https://github.com/fearlessgeekmedia/FearlessCMS/tree/0.1.4'
tags:
  - cve.org
  - exploit-available
epss: 0.00544
epssPercentile: 0.45703
ingestedAt: '2026-10-29T15:37:07.556Z'
---

## Overview

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.

## Affected

- `FearlessCMS < 0.1.4`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.