CVE-2026-2468: Quentn WP Plugin SQL Injection Vulnerability

CVE-2026-2468 Overview

CVE-2026-2468 is a SQL Injection vulnerability affecting the Quentn WP plugin for WordPress in all versions up to and including 1.2.12. The flaw resides in the get_user_access() method, which fails to properly escape user-supplied input from the qntn_wp_access cookie and lacks sufficient query preparation. Unauthenticated attackers can append additional SQL queries to existing database queries to extract sensitive information. The vulnerability is classified under [CWE-89] (Improper Neutralization of Special Elements used in an SQL Command).

Critical Impact
Unauthenticated attackers can exfiltrate sensitive data from the WordPress database, including user credentials, session tokens, and private content, by manipulating the qntn_wp_access cookie value.

Affected Products

Quentn WP plugin for WordPress — all versions up to and including 1.2.12
WordPress sites running the vulnerable class-quentn-wp-restrict-access.php component
Installations exposing the qntn_wp_access cookie to untrusted clients

Discovery Timeline

2026-03-21 - CVE-2026-2468 published to the National Vulnerability Database
2026-04-22 - Last updated in NVD database

Technical Details for CVE-2026-2468

Vulnerability Analysis

The vulnerability stems from unsafe handling of the qntn_wp_access cookie inside the plugin's access control logic. The get_user_access() method, located in includes/class-quentn-wp-restrict-access.php around line 483, reads the cookie value and incorporates it into a SQL statement without parameterized queries or proper escaping. WordPress provides safe query primitives such as $wpdb->prepare(), but the affected code path bypasses these safeguards.

Because the injection point is a cookie, attackers do not need authentication or user interaction. Any request sent to a protected resource that triggers get_user_access() evaluation is sufficient to deliver the payload. The flaw enables UNION-based and boolean-based blind SQL injection techniques, both of which support extraction of arbitrary table contents from the WordPress database.

Root Cause

The root cause is insufficient input neutralization combined with the absence of prepared statements. The plugin treats the qntn_wp_access cookie as trusted data and concatenates it directly into a SQL string. This pattern is a textbook [CWE-89] flaw and is mitigated only by using $wpdb->prepare() with placeholders or by strictly validating cookie input against an expected format before query construction.

Attack Vector

Exploitation occurs over the network with no privileges and no user interaction. An attacker crafts an HTTP request to a WordPress site running the vulnerable plugin and sets the qntn_wp_access cookie to a malicious SQL payload. When the plugin processes the request, the injected SQL executes against the WordPress database. The attacker can then read sensitive tables such as wp_users, retrieve password hashes, session tokens, and configuration secrets stored by other plugins.

No verified proof-of-concept code is publicly available at this time. Technical details about the vulnerable function are documented in the WordPress Plugin Code Reference and the Wordfence Vulnerability Report.

Detection Methods for CVE-2026-2468

Indicators of Compromise

HTTP requests containing SQL syntax characters such as UNION, SELECT, SLEEP(, --, or ' within the qntn_wp_access cookie header.
Unusual outbound database query patterns from the WordPress host targeting tables like wp_users or wp_options.
Web server access logs showing repeated requests from a single source with varying cookie payloads, indicating blind injection enumeration.

Detection Strategies

Inspect web application firewall (WAF) logs for SQL keywords appearing in cookie headers, focusing on the qntn_wp_access parameter.
Enable WordPress database query logging and look for malformed or unexpected queries originating from the Quentn WP plugin.
Correlate spikes in 500-level HTTP responses with cookie-based request anomalies to identify injection probing activity.

Monitoring Recommendations

Monitor authentication tables for unauthorized read access patterns and bulk row retrievals.
Alert on any request whose cookie length or character distribution deviates significantly from baseline.
Track plugin version inventory across WordPress installations and flag any host running Quentn WP 1.2.12 or earlier.

How to Mitigate CVE-2026-2468

Immediate Actions Required

Identify all WordPress installations running the Quentn WP plugin and confirm the installed version.
Deactivate the Quentn WP plugin on any site running version 1.2.12 or earlier until a patched release is installed.
Rotate WordPress administrator passwords, API keys, and secrets that may have been exposed through the vulnerable database.
Review access logs for the period since the plugin was deployed to detect prior exploitation attempts.

Patch Information

At the time of publication, the vulnerability affects all versions up to and including 1.2.12. Site administrators should update to a fixed release as soon as the vendor publishes one. Monitor the Wordfence Vulnerability Report and the WordPress Plugin Development File for fix availability and changelog details.

Workarounds

Deploy a WAF rule that blocks or sanitizes requests containing SQL metacharacters in the qntn_wp_access cookie.
Restrict access to WordPress sites using the plugin via IP allowlisting on administrative and protected endpoints.
Temporarily disable the Quentn WP plugin until an official patched version is released and verified in a staging environment.

bash

# Example WAF rule (ModSecurity) blocking SQLi patterns in the qntn_wp_access cookie
SecRule REQUEST_COOKIES:qntn_wp_access "@rx (?i)(union(\s|/\*.*\*/)+select|sleep\s*\(|benchmark\s*\(|--|';)" \
    "id:1002468,phase:1,deny,status:403,log,msg:'CVE-2026-2468 SQLi attempt in qntn_wp_access cookie'"