CVE-2026-63190：FearlessCMS 未授權除錯指令碼暴露檔案操作與 XSS 漏洞
CVE-2026-63190 - FearlessCMS: Unauthenticated debug scripts expose filesystem operations and XSS
FearlessCMS 在 0.1.4 之前的版本存在未授權除錯指令碼，允許攻擊者寫入任意檔案、執行 XSS 以及耗盡磁碟空間。
- 漏洞範圍：五個位於
admin/的 PHP 除錯指令碼缺少isLoggedIn()、CSRF 防護與路徑驗證。
此漏洞允許未授權者執行任意檔案寫入、XSS 與磁碟耗盡，讀者可即時評估更新或加固措施。
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.
Impact
Affected Products
The following products are affected by CVE-2026-63190
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
| ID | Vendor | Product | Action |
|---|---|---|---|
| 1 | Fearlessgeekmedia | fearlesscms |
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | MITRE-CVE | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Update FearlessCMS to version 0.1.4 or later to address authentication bypass and file manipulation vulnerabilities.
- Update FearlessCMS to version 0.1.4.
- Apply vendor patches if updating is not possible.
- Review and secure admin scripts.
- Restrict filesystem access.
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63190.
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63190 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63190
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63190 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63190 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
十月. 28, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L Added CWE CWE-79 Added CWE CWE-22 Added CWE CWE-200 Added CWE CWE-306 Added CWE CWE-288 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/63xxx/CVE-2026-63190.json">CVE-2026-63190</a> Added Reference https://github.com/fearlessgeekmedia/FearlessCMS/commit/59fb22cf989b5ba14c387c3212e15b146e02cf9a Added Reference https://github.com/fearlessgeekmedia/FearlessCMS/security/advisories/GHSA-3mq8-hrhf-7hv6 Added Reference https://github.com/fearlessgeekmedia/FearlessCMS/tree/0.1.4
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.