CVE-2026-2831: 
WordPress vulnerability analysis and mitigation

CVE-2026-2831 is an authenticated SQL Injection vulnerability in the MailArchiver plugin for WordPress, affecting all versions up to and including 4.5.0. The flaw exists in the logid parameter due to insufficient escaping of user-supplied input and inadequate SQL query preparation. It was published on February 27, 2026, with Wordfence credited as the assigner. The vulnerability carries a CVSS v3.1 base score of 4.9 (Medium), requiring Administrator-level authentication to exploit (Wordfence, ENISA EUVD).

The root cause is classified as CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), arising from insufficient escaping of the logid parameter and lack of prepared statements in the plugin's SQL queries. Specifically, the vulnerable code paths are found in includes/features/class-eventviewer.php (line 79) and includes/features/class-events.php (line 614) in version 4.5.0. An authenticated attacker with Administrator-level access can append additional SQL queries to existing ones via the logid parameter over the network, enabling extraction of sensitive data from the WordPress database (Wordfence, WordPress Trac).

Successful exploitation allows an authenticated administrator-level attacker to extract sensitive information from the WordPress database, including user credentials, email archives, configuration data, and other stored content. The confidentiality impact is rated High, while integrity and availability are unaffected. Because exploitation requires Administrator-level access, the practical blast radius is limited to scenarios where an attacker has already compromised an admin account or is a malicious insider (ENISA EUVD, Wordfence).

No public exploit code or active in-the-wild exploitation has been reported for CVE-2026-2831. The EPSS score is approximately 0.023% (0.000230), indicating a very low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation is constrained by the requirement for Administrator-level authentication, significantly reducing the attack surface (Wordfence, ENISA EUVD).

1. Authentication: Log in to the WordPress site with an Administrator-level account (or higher).
2. Identify the vulnerable endpoint: Navigate to the MailArchiver plugin's event viewer or log viewer interface, which processes the logid parameter in its backend queries.
3. Craft a malicious payload: Append SQL injection syntax to the logid parameter (e.g., logid=1 UNION SELECT user_login,user_pass,NULL FROM wp_users--) to extend the existing SQL query.
4. Submit the request: Send the crafted HTTP request (via browser, Burp Suite, or sqlmap) to the vulnerable endpoint handling logid.
5. Extract data: Retrieve the injected query results from the application's response, exposing sensitive database contents such as WordPress user credentials or archived email data (Wordfence, WordPress Trac).

• Logs: WordPress access logs showing unusual or malformed values in the logid parameter (e.g., SQL keywords such as UNION, SELECT, --, OR 1=1) in requests to MailArchiver admin pages.
• Database: Unexpected or anomalous database query patterns in MySQL/MariaDB slow query logs or general query logs involving the MailArchiver tables with appended SQL clauses.
• Network: Repeated or automated HTTP requests to WordPress admin endpoints associated with MailArchiver's event viewer from a single IP, potentially indicating automated SQL injection tooling (e.g., sqlmap user-agent strings).
• File System: No specific file artifacts are expected, as this is a network-based SQL injection with no file write capability indicated.

Users should update the MailArchiver plugin to a version beyond 4.5.0 that addresses this SQL injection vulnerability. As an interim measure, administrators can restrict access to the WordPress admin panel using IP allowlisting or web application firewall (WAF) rules that block SQL injection patterns in the logid parameter. Monitoring WordPress admin activity logs for anomalous query patterns is also recommended while a patch is applied (Wordfence, ENISA EUVD).

Wordfence, which discovered and disclosed the vulnerability, published the advisory through their threat intelligence platform. No significant broader media coverage, notable researcher commentary, or social media discussion has been identified for this vulnerability, consistent with its medium severity and high privilege requirement.