CVE-2026-40771: Contest Gallery SQL Injection Flaw

CVE-2026-40771 Overview

CVE-2026-40771 is an unauthenticated SQL Injection vulnerability affecting the Contest Gallery WordPress plugin in versions up to and including 28.1.6. The flaw allows remote attackers to inject arbitrary SQL statements through user-controlled input without requiring authentication or user interaction. The vulnerability is classified under [CWE-89] (Improper Neutralization of Special Elements used in an SQL Command).

The issue carries a CVSS 3.1 base score of 9.3 and was published to the National Vulnerability Database on June 15, 2026. Attackers can leverage the flaw over the network to read sensitive database content and disrupt site availability.

Critical Impact
Unauthenticated attackers can execute arbitrary SQL queries against the WordPress database, exposing user credentials, session data, and configuration secrets stored by the Contest Gallery plugin.

Affected Products

Contest Gallery WordPress plugin versions <= 28.1.6
WordPress sites with the Contest Gallery plugin installed and activated
Any environment exposing the plugin endpoints to untrusted network traffic

Discovery Timeline

2026-06-15 - CVE-2026-40771 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-40771

Vulnerability Analysis

The Contest Gallery plugin fails to properly neutralize special elements within SQL statements built from user-supplied parameters. An attacker submits crafted input to a vulnerable plugin endpoint, and the input is concatenated into a SQL query without parameterization or adequate sanitization. The database engine then executes the attacker-controlled SQL fragment with the privileges of the WordPress database user.

Because exploitation requires no authentication and no user interaction, any internet-exposed WordPress site running a vulnerable version is reachable. The CVSS scope is marked as changed, indicating that the impact extends beyond the vulnerable component to other database resources accessible by the WordPress credentials. The EPSS probability stands at 0.283% as of June 18, 2026, placing the CVE in the 19.8 percentile for likelihood of exploitation activity.

Root Cause

The root cause is missing input neutralization on parameters passed to SQL queries inside the Contest Gallery plugin. The plugin constructs queries through string concatenation instead of using prepared statements such as $wpdb->prepare(). This pattern is the canonical [CWE-89] anti-pattern in WordPress plugin code.

Attack Vector

The attack vector is Network. A remote attacker sends HTTP requests to a Contest Gallery plugin endpoint with malicious SQL payloads embedded in request parameters. No credentials or victim interaction are required. Successful exploitation can be used to enumerate database contents, extract wp_users password hashes, or trigger conditions that degrade availability.

Technical details are documented in the Patchstack SQL Injection Vulnerability advisory.

Detection Methods for CVE-2026-40771

Indicators of Compromise

HTTP requests to Contest Gallery plugin endpoints containing SQL metacharacters such as UNION SELECT, SLEEP(, BENCHMARK(, --, 0x, or information_schema
Unusual outbound database queries referencing wp_users, wp_usermeta, or wp_options originating from plugin request handlers
Spikes in 500-level responses or query latency tied to Contest Gallery request paths
New or modified administrator accounts and unexpected entries in wp_options shortly after suspicious plugin requests

Detection Strategies

Inspect web server access logs for parameter values containing SQL syntax delivered to Contest Gallery endpoints
Deploy or tune Web Application Firewall (WAF) rules that match SQL injection signatures for WordPress plugins
Compare installed plugin versions against 28.1.6 and flag any host running a vulnerable build
Correlate web request anomalies with downstream MySQL slow-query or error log entries

Monitoring Recommendations

Forward WordPress, web server, and MySQL logs into a centralized analytics platform for query-time-aware correlation
Alert on wp_users table reads originating from front-end plugin contexts rather than wp-admin
Track plugin file integrity and configuration changes for unauthorized modifications

How to Mitigate CVE-2026-40771

Immediate Actions Required

Identify every WordPress instance with Contest Gallery installed and confirm the version against 28.1.6
Upgrade the Contest Gallery plugin to the fixed release referenced in the Patchstack advisory
If patching is not immediately possible, deactivate and remove the plugin until remediation is applied
Rotate WordPress administrator passwords, secret keys in wp-config.php, and any database credentials that may have been exposed

Patch Information

Refer to the Patchstack SQL Injection Vulnerability advisory for the patched version of Contest Gallery and upgrade instructions. Apply the vendor-supplied update through the WordPress plugin manager or by deploying the fixed plugin package.

Workarounds

Restrict access to Contest Gallery endpoints via WAF rules that block SQL injection patterns and anonymous parameter tampering
Enforce least-privilege on the WordPress database account so plugin queries cannot read or modify unrelated schemas
Disable the Contest Gallery plugin until the patched release is deployed and verified

bash

# Example WP-CLI workflow to inventory and disable the vulnerable plugin
wp plugin list --name=contest-gallery --fields=name,status,version
wp plugin deactivate contest-gallery
wp plugin update contest-gallery