CVE-2026-78262 in Project Manager Plugin
Summary
by MITRE • 08/25/2026
Unauthenticated PHP Object Injection in WP Project Manager <= 4.0.6 versions.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/25/2026
The vulnerability identified as an unauthenticated PHP object injection flaw within WP Project Manager versions 4.0.6 and earlier represents a critical security risk that allows attackers to execute arbitrary code on the target server without requiring valid user credentials. This type of vulnerability stems from the improper handling of serialized data, where the application accepts input parameters that are directly passed into PHP's unserialize function or similar deserialization mechanisms without adequate validation or sanitization. In the context of WordPress plugins like WP Project Manager, this often occurs when processing AJAX requests or form submissions related to project management tasks such as creating new projects, updating task statuses, or managing team assignments. The attacker crafts a malicious payload containing a serialized PHP object with properties that trigger dangerous magic methods during deserialization, leading to remote code execution or other severe backend compromises.
From a technical perspective, the core issue lies in the lack of strict type checking and input validation on user-supplied data before it is processed by internal functions designed for handling complex data structures. When an application relies on PHP's automatic unserialization capabilities without verifying the integrity of the incoming serialized string, it becomes susceptible to gadget chain exploitation. Attackers can leverage publicly available libraries or components included in the WordPress environment and its plugins to construct a payload that exploits known vulnerable classes. This process typically involves identifying accessible classes with magic methods such as __wakeup, __destruct, or __toString, which are invoked automatically during object instantiation from serialized data. By chaining these method calls, an attacker can achieve arbitrary file writes, database manipulation, or complete system control depending on the available context and permissions of the web server process.
The operational impact of this vulnerability is severe, as it effectively bypasses all authentication mechanisms provided by WordPress and the plugin itself. An unauthenticated remote code execution flaw means that any internet user with access to the vulnerable endpoint can exploit the issue without prior login or privilege escalation steps. This significantly lowers the barrier for entry, allowing automated scanning tools and opportunistic attackers to compromise sites rapidly. Once exploited, the attacker gains full control over the web application's backend environment. They can exfiltrate sensitive data including customer information, financial records, and administrative credentials stored in the WordPress database. Furthermore, they may install persistent backdoors, modify website content for defacement or phishing campaigns, use the compromised server as a pivot point to attack internal networks, or engage in cryptomining operations using the victim's resources.
This vulnerability aligns with CWE-502, which describes Deserialization of Untrusted Data, and is frequently associated with CWE-94, Improper Control of Generation of Code (Code Injection). In terms of offensive security frameworks like MITRE ATT&CK, this exploitation technique falls under the category of Initial Access via Web Applications, specifically leveraging server-side request forgery or code injection vectors. The lack of authentication required for exploitation places it in a high-severity tier within vulnerability scoring systems such as CVSS, often receiving maximum scores due to its remote nature and potential for full system compromise. Organizations relying on this plugin are at significant risk because the flaw exists in core functionality that is likely exposed through standard WordPress REST API endpoints or AJAX handlers commonly accessed by legitimate users.
To mitigate this critical issue, immediate action must be taken to update WP Project Manager to version 4.0.7 or later where the vulnerability has been patched. The patch typically involves implementing strict input validation, ensuring that only expected data types are processed and preventing arbitrary object instantiation from user-controlled inputs. If updating is not immediately feasible due to compatibility concerns with other plugins or custom code modifications, administrators should consider disabling the specific AJAX endpoints associated with project creation or management if they are not actively used. Additionally, deploying a Web Application Firewall can provide a layer of defense by blocking requests containing known malicious serialized payloads or patterns indicative of PHP object injection attempts. It is also crucial to review server-side configurations to limit the impact of potential exploitation, such as restricting file write permissions and ensuring that database accounts have minimal necessary privileges. Regular security audits and penetration testing should be conducted to identify similar deserialization flaws in other plugins and custom code within the WordPress ecosystem.