CVE-2026-84221 in Kirki Plugin
Summary
by MITRE • 09/05/2026
The Kirki WordPress plugin before 6.3.0 does not escape a user-supplied identifier before using it in a SQL query, allowing users with editor-level access and above to append arbitrary SQL and read the contents of the database, including user credentials.
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Analysis
by VulDB Data Team • 09/07/2026
The vulnerability identified in Kirki versions prior to 6.3.0 represents a critical security flaw rooted in improper input validation and sanitization within the plugin's administrative interface. Specifically, the issue arises from an Unrestricted SQL Upload scenario where a user-supplied identifier is passed directly into a database query without adequate escaping or parameterization. This architectural weakness allows authenticated attackers with editor-level access or higher privileges to manipulate backend data structures by injecting malicious SQL code. The root cause lies in the failure of the application logic to distinguish between legitimate configuration parameters and executable commands, thereby violating fundamental principles of secure coding practices regarding input handling.
From a technical perspective, this flaw constitutes an instance of CWE-89 Improper Neutralization of Special Elements used in an SQL Command commonly known as SQL Injection. By appending arbitrary SQL statements to the identifier field, an attacker can alter the intended logic of the database query. This capability enables the extraction of sensitive information stored within the WordPress database. The impact is severe because it allows for the exfiltration of user credentials, including hashed passwords and potentially plaintext authentication tokens if weak hashing algorithms are in use. Furthermore, access to such data facilitates further lateral movement within the network environment, as compromised administrative accounts can be used to install additional malicious plugins or modify site configurations to maintain persistence.
The operational impact extends beyond simple data theft. An attacker leveraging this vulnerability can achieve unauthorized read access to the entire database schema and contents. This includes retrieving session keys, API tokens, and other sensitive metadata that are critical for maintaining secure communications between WordPress instances and external services. The ability to execute arbitrary SQL also opens the door to potential write operations depending on the specific query context and database permissions granted to the web server process. Such actions could lead to data integrity violations where attacker-controlled content is injected into posts or settings, potentially facilitating cross-site scripting attacks against end-users who view the compromised site content.
Mitigation strategies must focus on immediate remediation of the vulnerable code path alongside broader security hardening measures. The primary and most effective solution is to upgrade the Kirki plugin to version 6.3.0 or later where this specific input validation flaw has been addressed by implementing proper parameterized queries or rigorous escaping mechanisms for all user-supplied identifiers. In addition to updating software, administrators should enforce strict role-based access control principles ensuring that only trusted users with administrative privileges can modify complex theme customizer settings if possible. Implementing a Web Application Firewall can provide an additional layer of defense by detecting and blocking common SQL injection patterns in HTTP requests before they reach the application logic. Regular security audits and code reviews are also recommended to identify similar vulnerabilities across other plugins installed on the WordPress instance, ensuring comprehensive protection against database-centric attacks aligned with MITRE ATT&CK techniques related to Credential Access and Data Exfiltration.