CVE-2026-111106 in Mail Mint Plugin
Summary
by MITRE • 10/16/2026
The Mail Mint plugin for WordPress is vulnerable to SQL Injection via the 'filters' parameter of the /wp-json/mrm/v1/segments/contacts REST endpoint in versions up to, and including, 1.31.4 This is due to insufficient escaping on the user supplied filter 'value' before it is appended to a SQL query in SegmentFilterService::get_meta_join_query() at line 797, where the value is string-interpolated into the WHERE fragment in a numeric (unquoted) context and the surrounding $wpdb->prepare() calls do not cover the injected value. This makes it possible for authenticated attackers, with the custom 'mint_read_contacts' capability (granted to Administrators by default, and configurable to lower roles via the plugin's role manager), to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.
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Analysis
by VulDB Data Team • 10/16/2026
The Mail Mint WordPress plugin contains a critical SQL injection vulnerability within its REST API implementation, specifically affecting versions up to and including 1.31.4. This flaw resides in the handling of user-supplied input for the 'filters' parameter associated with the /wp-json/mrm/v1/segments/contacts endpoint. The root cause is identified as insufficient escaping mechanisms applied to the filter value before it is integrated into a database query structure. In the SegmentFilterService::get_meta_join_query method, located at line 797 of the plugin codebase, the application performs string interpolation directly on the user-provided value. This operation places the input into a WHERE clause fragment within a numeric context that expects unquoted values. Although the surrounding code utilizes WordPress's $wpdb->prepare function for general query safety, this specific interpolated segment falls outside the scope of those protective measures, leaving it vulnerable to manipulation by malicious actors who can inject arbitrary SQL syntax.
The operational impact of this vulnerability is significant due to its potential for data exfiltration and database compromise. Because the injection occurs in a numeric context without proper quoting or sanitization, an attacker can append additional SQL statements to existing queries. This capability allows for blind SQL injection techniques where the attacker can extract sensitive information from the WordPress database, such as user credentials, session tokens, or other proprietary data stored within the site's tables. The vulnerability is classified under CWE-89, which denotes Improper Neutralization of Special Elements used in an SQL Command, highlighting the failure to properly sanitize input before its use in a dynamic query construction process. This type of flaw often leads to severe confidentiality breaches and can serve as a stepping stone for further attacks against the underlying server infrastructure if database privileges are overly permissive.
Accessing this vulnerability requires authentication, which serves as a limiting factor but does not eliminate the risk entirely. The exploitability is contingent upon the attacker possessing at least the custom 'mint_read_contacts' capability granted by the plugin's role manager. By default, this capability is assigned to Administrators, meaning that any compromised administrator account can be leveraged to execute these malicious queries. However, since WordPress plugins often allow administrators to assign capabilities to lower-level roles such as Editors or Authors via configuration settings, the attack surface expands significantly if those permissions are granted to less privileged users. This aligns with ATT&CK technique T1059, Command and Scripting Interpreter, specifically through SQL commands used for data exfiltration, demonstrating how authenticated access can be abused to interact directly with backend systems in unauthorized ways.
Mitigation strategies must focus on both immediate remediation and long-term security hardening. The primary defense is the prompt upgrade of the Mail Mint plugin to a version later than 1.31.4 where this specific input validation flaw has been addressed by the developers through proper parameterization or escaping techniques. In instances where upgrading is not immediately feasible, administrators should restrict the 'mint_read_contacts' capability to only those users who absolutely require it for their job functions, thereby reducing the number of potential attack vectors. Additionally, implementing a Web Application Firewall can provide an additional layer of defense by detecting and blocking common SQL injection patterns in REST API requests before they reach the application logic. Regular security audits and code reviews focusing on database interaction layers are also recommended to identify similar vulnerabilities across other plugins or custom themes that may share architectural similarities with this flawed implementation.