CVE-2026-15302 in ARMember Plugin
Summary
by MITRE • 07/10/2026
The ARMember plugin for WordPress is vulnerable to Directory Traversal in all versions up to, and including, 4.0.27 via the 'X-FILENAME' HTTP header. This makes it possible for unauthenticated attackers to upload and overwrite certain files (e.g., CSS) to directories outside the 'wp-content/uploads/armember' directory.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/10/2026
The ARMember plugin for WordPress presents a critical directory traversal vulnerability that affects all versions up to and including 4.0.27 through improper handling of the X-FILENAME HTTP header. This flaw originates from insufficient input validation and sanitization within the file upload mechanism, allowing attackers to manipulate the target directory path during file operations. The vulnerability specifically manifests when the plugin processes file uploads with the X-FILENAME header, which should normally contain only a filename but can be exploited to traverse parent directories using sequences like ../. This weakness creates a pathway for unauthenticated attackers to bypass normal access controls and write files outside of the intended upload directory structure.
The technical implementation of this vulnerability stems from inadequate path validation routines within the plugin's file handling code. When processing the X-FILENAME header, the system fails to properly sanitize or validate the input before incorporating it into the file system operations. This allows attackers to inject malicious path sequences that alter the intended destination of uploaded files. The affected directory structure typically includes the wp-content/uploads/armember folder where legitimate uploads should occur, but due to the lack of proper boundary checks, attackers can specify arbitrary paths outside this designated area. The vulnerability is particularly dangerous because it enables attackers to overwrite existing files or create new ones in strategic locations within the WordPress installation.
The operational impact of this directory traversal vulnerability extends beyond simple file manipulation and represents a significant security risk for WordPress installations. Attackers can leverage this weakness to upload malicious files such as php shells, webshells, or modified css files that could be executed by the web server. The ability to overwrite existing CSS files provides attackers with a method to inject malicious code into legitimate website assets, potentially leading to cross-site scripting attacks or serving as a foothold for further exploitation. Additionally, the vulnerability allows for potential privilege escalation if attackers can target configuration files or other sensitive resources within the WordPress directory structure.
Mitigation strategies should focus on immediate patching of the ARMember plugin to version 4.0.28 or later, which addresses the directory traversal flaw through proper input sanitization and path validation. Organizations should implement network-level restrictions to limit access to the affected plugin endpoints and monitor for suspicious file upload activities. Security measures including web application firewalls should be configured to detect and block requests containing directory traversal sequences in HTTP headers. The vulnerability aligns with CWE-22 Directory Traversal and follows ATT&CK techniques related to privilege escalation through file system manipulation. Regular security audits of WordPress plugins should include verification of input validation practices and proper implementation of file system access controls to prevent similar vulnerabilities from emerging in other components of the web application stack.