CVE-2026-66627 in GP Premium Plugin
Summary
by MITRE • 08/18/2026
Contributor Arbitrary File Upload in GP Premium <= 2.5.5 versions.
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Analysis
by VulDB Data Team • 08/18/2026
The vulnerability identified as Contributor Arbitrary File Upload in GP Premium versions prior to or equal to 2.5.5 represents a critical security flaw within the WordPress ecosystem, specifically affecting sites utilizing the Genesis Framework and its associated premium plugin suite. This issue stems from insufficient validation of file uploads initiated by users with lower-level privileges, such as contributors or authors, rather than just administrators. In typical web application architecture, privilege escalation vulnerabilities allow attackers to perform actions reserved for higher-privileged roles, thereby compromising the integrity and confidentiality of the entire system. The core technical flaw lies in the handling of media library interactions where the plugin fails to adequately verify that a user uploading a file possesses the necessary administrative capabilities or strictly restricts uploadable file types based on their role level.
From a technical perspective, this vulnerability allows an authenticated attacker with contributor-level access to bypass standard security controls and execute arbitrary code by uploading malicious files such as PHP scripts, web shells, or other executable payloads directly into the WordPress uploads directory. Unlike unauthenticated remote code execution vulnerabilities which require no prior login, this specific flaw requires initial authentication but significantly lowers the barrier for entry since obtaining contributor credentials is often easier than acquiring administrator access through social engineering or brute force attacks. The attacker can leverage these uploaded files to gain full control over the web server hosting the WordPress instance, leading to complete system compromise including data theft, defacement, and use of the compromised host as a pivot point for further network intrusions.
The operational impact of this vulnerability is severe due to its potential for widespread exploitation across numerous websites running vulnerable versions of GP Premium. Once an attacker successfully uploads a web shell, they can execute arbitrary commands on the server, manipulate database contents containing sensitive user information and business logic, and potentially install additional malware such as cryptominers or botnet clients. This not only results in direct financial loss and reputational damage for site owners but also contributes to broader cybersecurity threats by turning legitimate websites into nodes within larger attack infrastructures used for distributed denial-of-service attacks or phishing campaigns targeting other organizations.
This vulnerability aligns with CWE-434, which describes the Unrestricted Upload of File with Dangerous Type, as well as CWE-269 regarding Improper Privilege Management because it exploits a failure to enforce proper access control policies based on user roles. In terms of offensive security frameworks like MITRE ATT&CK, this flaw facilitates techniques associated with Initial Access through Valid Accounts and Execution via Web Shell Uploads, allowing adversaries to establish persistence within the compromised environment without triggering typical intrusion detection systems that focus solely on external threats or high-privilege actions.
To mitigate this risk, site administrators must immediately update GP Premium to version 2.5.6 or later where these validation checks have been strengthened and role-based restrictions are properly enforced. For sites unable to patch immediately due to compatibility concerns with other plugins, temporary mitigation strategies include restricting file upload permissions via server-level configurations such as disabling PHP execution in the uploads directory using .htaccess rules on Apache servers or equivalent configuration blocks for Nginx environments. Additionally implementing strict Content Security Policies and utilizing Web Application Firewalls can help detect and block attempts to execute uploaded scripts, although these are secondary controls compared to applying the official vendor patch which addresses the root cause of inadequate input validation and privilege checking within the plugin codebase itself.