CVE-2026-116867 in Dynamic QR Code Plugin
Summary
by MITRE • 10/29/2026
Contributor PHP Object Injection in Dynamic QR Code – generator <= 1.0.1 versions.
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Analysis
by VulDB Data Team • 10/29/2026
The vulnerability identified as Contributor PHP Object Injection in the Dynamic QR Code Generator plugin, affecting versions up to and including 1.0.1, represents a critical security flaw rooted in improper input validation and unsafe deserialization practices within the WordPress ecosystem. This specific type of attack leverages the mechanism known as PHP Object Injection, where an attacker manipulates serialized data structures that are subsequently passed through unserialized functions without adequate sanitization or verification of object types. In the context of this plugin, which is designed to generate dynamic QR codes for various content such as URLs, text, and contact information, the flaw likely resides in how user-supplied input from form fields or API requests is processed before being stored or rendered. When an application accepts serialized PHP objects from untrusted sources and passes them directly into functions like unserialize() without strict type checking or allowlisting of expected classes, it creates a pathway for malicious actors to inject arbitrary object instances that can trigger unintended side effects during their instantiation methods.
From a technical perspective, this vulnerability falls under the category of CWE-502, which denotes Deserialization of Untrusted Data. The core issue is not merely about injecting code but rather exploiting the lifecycle hooks inherent in PHP objects, such as __wakeup(), __destruct(), or other magic methods that execute automatically when an object is instantiated from serialized data. If the vulnerable plugin instantiates user-controlled input into a class that has access to sensitive file system operations, database interactions, or remote function calls, an attacker can craft a payload that forces these objects to perform actions outside their intended scope. For instance, if there exists a class within the plugin or its dependencies capable of writing files to the server's directory structure, an injected object could overwrite critical configuration files, upload web shells, or modify existing scripts to establish persistent backdoors. This transforms what appears as a simple QR code generation tool into a vector for full system compromise.
The operational impact of this vulnerability is severe and multifaceted, primarily centering on the potential for Remote Code Execution (RCE) and privilege escalation within the WordPress environment. Since WordPress plugins typically run with the same permissions as the web server process, successful exploitation allows an attacker to execute arbitrary PHP code on the host machine. This can lead to complete control over the website's backend, enabling the theft of sensitive data such as user credentials, database contents, or proprietary business information stored within the site. Furthermore, because WordPress sites are often interconnected through shared hosting environments or common themes and plugins, a compromised instance can serve as a pivot point for lateral movement across the network infrastructure. Attackers may also use this access to deface the website, deploy malware on visitor devices via drive-by downloads linked from the QR codes, or utilize the server's resources for cryptomining and distributed denial-of-service attacks, thereby degrading service availability for legitimate users.
In terms of industry classification frameworks, this vulnerability aligns with MITRE ATT&CK technique T1059, specifically Command and Scripting Interpreter: PHP, as it involves executing code through interpreted languages on the target system. It also relates to T1190, Exploit Public-Facing Application, given that plugins are accessible via HTTP requests from external users. The attack vector typically requires low privileges if the vulnerability is exploitable by unauthenticated visitors accessing public-facing forms or endpoints within the plugin; however, in some configurations, it might require authenticated access with lower-level roles such as subscriber or contributor, depending on how capability checks were implemented around the vulnerable function. Regardless of the required privilege level, the ability to inject objects signifies a fundamental failure in input validation boundaries between user data and system logic.
Mitigation strategies for this vulnerability must prioritize immediate remediation through software updates alongside robust defensive coding practices. The most effective solution is to upgrade the Dynamic QR Code Generator plugin to version 1.0.2 or later, where developers have presumably addressed the deserialization flaw by implementing strict type checking, using whitelists of allowed classes during unserialization, or replacing object-based storage with safer data formats like JSON for non-object payloads. For organizations unable to update immediately due to compatibility constraints, temporary mitigations include restricting access to the plugin's administrative interfaces through IP allowlisting if feasible, disabling PHP execution in upload directories to prevent shell deployment, and employing a Web Application Firewall (WAF) configured to detect patterns associated with serialized object injection attempts. Additionally, auditing other plugins for similar deserialization vulnerabilities is crucial, as this pattern of insecure coding can exist across multiple components within the same WordPress installation, creating compound risks that extend beyond the initial entry point identified in this specific CVE context.