CVE-2026-89303 in Post Voting System Plugin
Summary
by MITRE • 09/28/2026
The Post Voting System WordPress plugin through 1.0 does not properly sanitize and escape a parameter before using it in a SQL query, allowing any authenticated user to perform SQL injection attacks.
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Analysis
by VulDB Data Team • 09/28/2026
The vulnerability identified within the Post Voting System WordPress plugin version 1.0 represents a critical security flaw rooted in insufficient input validation and output encoding mechanisms. Specifically, the application fails to properly sanitize or escape user-supplied parameters prior to their incorporation into Structured Query Language statements executed against the backend database. This architectural oversight creates an avenue for SQL injection attacks, which are among the most prevalent and dangerous web application vulnerabilities as categorized under CWE-89 in the Common Weakness Enumeration standard. The flaw is particularly severe because it does not require administrative privileges or complex exploitation chains; rather, any authenticated user can leverage this weakness to manipulate database queries directly.
From a technical perspective, the absence of parameterized queries or rigorous escaping functions allows an attacker to inject malicious SQL code into legitimate requests. By manipulating specific input fields associated with post voting activities, such as vote counts or user identifiers, an adversary can alter the logic of the underlying SQL commands. This capability enables the extraction of sensitive data stored within the WordPress database, including user credentials, personal information, and site configuration details. Furthermore, depending on the database engine and its permissions, this vulnerability could potentially allow for unauthorized modifications to existing records or even the execution of operating system commands if specific database features are enabled and misconfigured.
The operational impact of this vulnerability extends beyond immediate data theft. An attacker with authenticated access can compromise the integrity of the entire WordPress installation by exfiltrating administrative credentials stored in plain text or hashed formats within the wp_users table. Once these credentials are obtained, the threat actor can escalate privileges to gain full control over the website backend. This level of access facilitates further malicious activities such as defacement, malware distribution, and using the compromised server as a pivot point for attacks against other internal network resources. The vulnerability aligns with ATT&CK technique T1059 Command and Scripting Interpreter through SQL commands, allowing attackers to execute arbitrary instructions within the database environment.
Mitigation strategies must prioritize immediate remediation of the codebase responsible for handling user inputs related to voting mechanisms. Developers should implement strict input validation to ensure that all parameters conform to expected data types and formats before processing. More importantly, the use of prepared statements with parameterized queries is essential to separate SQL logic from data, thereby neutralizing injection attempts regardless of the content provided by users. Additionally, applying the principle of least privilege ensures that the database user account used by WordPress has only the necessary permissions for its function, limiting the potential damage even if an injection occurs. Upgrading to a patched version of the plugin or replacing it with a more secure alternative is the most effective long-term solution to eliminate this risk vector entirely.