CVE-2026-71426 in GetSimple CMS
Summary
by MITRE • 10/01/2026
GetSimple CMS is a content management system (CMS), and GetSimple CMS CE is the community edition of that CMS. In versions 3.3.22 and prior, an authenticated user with page-editing rights can store an arbitrary filesystem path in a page's template attribute. On the public front-end, this value is passed unsanitized to a PHP include() when the page is rendered. Because the include path is never confined, this allows directory-traversal Local File Inclusion: arbitrary local files are included (and, if they contain PHP, executed) when any visitor requests the page. At time of publication, there are no publicly available patches.
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Analysis
by VulDB Data Team • 10/01/2026
GetSimple CMS version 3.3.22 and earlier contains a critical security vulnerability that allows authenticated users with page-editing privileges to execute arbitrary code on the server through Local File Inclusion. This flaw stems from improper input validation within the content management system's template handling mechanism, specifically affecting how page attributes are processed during rendering. The vulnerability is particularly severe because it does not require administrative access or complex exploitation techniques; rather, it leverages standard user permissions to inject malicious payloads into the application logic.
The technical root cause lies in the unsanitized storage and subsequent use of a filesystem path within a page's template attribute field. When an authenticated user with editing rights modifies a page, they can input arbitrary strings that represent valid or invalid file system paths rather than legitimate template identifiers. These inputs are stored directly into the database without adequate sanitization checks to ensure they conform to expected formats or remain within allowed directories. This lack of validation creates a direct injection point for path manipulation attacks.
During the rendering phase, when a visitor requests the affected page from the public front-end, GetSimple CMS retrieves the template attribute and passes it directly into PHP's include() function without any further processing or restriction. Because the application does not confine the inclusion scope to a specific directory structure, an attacker can utilize standard directory traversal sequences such as dot-dot-slash to navigate up the file system hierarchy. This allows the inclusion of arbitrary local files located outside the intended web root or template directories.
The operational impact of this vulnerability is significant, leading primarily to Remote Code Execution and Local File Inclusion attacks. If the included file contains PHP code, it will be executed by the server with the same privileges as the web application process. This effectively grants an attacker full control over the underlying system, enabling them to read sensitive configuration files, exfiltrate database credentials, or deploy backdoors for persistent access. Even if no executable code is present in the included file, attackers can still use this vector to disclose confidential information stored on the server, such as private keys, user data, and internal network configurations.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifiers including CWE-94 Improper Control of Generation of Code or Script known as Injection, specifically Local File Inclusion, and CWE-20 Improper Input Validation. From a tactical perspective, this attack vector corresponds to the ATT&CK technique T1505.003 Server Side Request Forgery via Web Components, although it is more accurately classified under file inclusion mechanisms that lead to code execution. The lack of path confinement represents a fundamental failure in secure coding practices regarding resource management and access control.
Mitigation strategies for this vulnerability are currently limited due to the absence of publicly available patches at the time of publication. Organizations running affected versions must implement immediate compensating controls to reduce risk. Web Application Firewalls can be configured to detect and block requests containing directory traversal patterns or suspicious include parameters in URLs. Additionally, administrators should restrict file upload permissions and ensure that PHP execution is disabled in directories where user-uploaded content might reside if applicable. Upgrading to a patched version as soon as it becomes available from the vendor remains the most effective long-term solution. Until then, limiting access to page-editing functions to only essential personnel can help reduce the attack surface by minimizing the number of accounts capable of exploiting this flaw.