CVE-2026-57636: wpForo Forum SQL Injection Vulnerability

CVE-2026-57636 Overview

CVE-2026-57636 is a SQL injection vulnerability affecting the wpForo Forum plugin for WordPress in versions up to and including 3.0.9. The flaw allows authenticated users with Contributor-level privileges to inject malicious SQL statements through vulnerable plugin parameters. Because Contributor accounts are frequently provisioned to guest authors and community members, the barrier to exploitation on affected forums is low.

The issue is classified under CWE-89: Improper Neutralization of Special Elements used in an SQL Command. Successful exploitation can expose sensitive database contents and impact site availability.

Critical Impact
Authenticated Contributors can extract confidential database records from WordPress installations running vulnerable wpForo Forum versions, with scope changes extending beyond the plugin's own privilege boundary.

Affected Products

wpForo Forum plugin for WordPress, versions <= 3.0.9
WordPress sites permitting Contributor-level registration with wpForo installed
Community and forum deployments relying on wpForo for discussion features

Discovery Timeline

2026-06-26 - CVE-2026-57636 published to NVD
2026-06-26 - Last updated in NVD database

Technical Details for CVE-2026-57636

Vulnerability Analysis

The vulnerability resides in wpForo Forum plugin code paths reachable by authenticated users holding the WordPress Contributor role. User-controlled input flows into a database query without adequate sanitization or parameterization. An attacker submits crafted values that break out of the intended query context and append attacker-controlled SQL clauses.

The issue is a Scope-Changed injection, meaning the vulnerable component grants access to data owned by other components of the WordPress stack. Attackers can enumerate WordPress user records, session tokens stored in wp_usermeta, and plugin secrets residing in wp_options. The attack requires network access to the WordPress site and low-complexity crafting of HTTP requests to authenticated endpoints.

Root Cause

The root cause is improper neutralization of SQL metacharacters in request parameters before concatenation into database queries. The plugin fails to apply $wpdb->prepare() or equivalent parameterization on data supplied by Contributor-authenticated requests. Missing input validation and reliance on trust boundaries defined by WordPress roles allow injection despite authentication.

Attack Vector

Exploitation requires an attacker to hold or obtain a Contributor account on the target WordPress site. The attacker sends a crafted HTTP request to the vulnerable wpForo endpoint containing SQL payloads in an affected parameter. Time-based, union-based, or boolean-based extraction techniques allow the attacker to exfiltrate arbitrary database contents. Refer to the Patchstack WPForo SQL Injection Vulnerability advisory for parameter-level details.

Detection Methods for CVE-2026-57636

Indicators of Compromise

Unusual HTTP POST or GET requests to wpForo endpoints containing SQL syntax such as UNION SELECT, SLEEP(, BENCHMARK(, or encoded quote characters
Spikes in slow database queries or elevated MySQL CPU tied to requests from Contributor sessions
New or unexpected administrator accounts created shortly after Contributor account activity
Access log entries showing repeated requests to the same wpForo action with incrementally changing payloads

Detection Strategies

Enable MySQL general query or slow-query logging and alert on information_schema reads originating from the WordPress database user
Deploy WordPress-aware web application firewall (WAF) signatures targeting SQL injection patterns on /wp-admin/admin-ajax.php and wpForo routes
Correlate WordPress authentication events with anomalous query volumes from Contributor accounts

Monitoring Recommendations

Audit the WordPress users and usermeta tables daily for role escalations or new privileged accounts
Monitor plugin version inventories to identify hosts still running wpForo <= 3.0.9
Alert on outbound data transfers from web servers hosting the forum, which may indicate database exfiltration

How to Mitigate CVE-2026-57636

Immediate Actions Required

Update the wpForo Forum plugin to the version released after 3.0.9 that addresses this issue as noted in the Patchstack advisory
Audit existing Contributor accounts and remove any that are inactive, unrecognized, or unnecessary
Rotate WordPress secret keys in wp-config.php and force password resets if compromise is suspected

Patch Information

Upgrade wpForo Forum to a version higher than 3.0.9. Patchstack tracks the fixed release in its advisory database. Apply the update through the WordPress plugin manager or via WP-CLI using wp plugin update wpforo, and verify the installed version afterward with wp plugin get wpforo.

Workarounds

Disable open user registration or restrict the default new-user role to Subscriber until the plugin is patched
Temporarily deactivate the wpForo plugin if patching cannot be performed immediately
Deploy a WAF rule that blocks SQL injection payloads on wpForo request parameters
Restrict the database account used by WordPress to the minimum privileges required, denying access to sensitive tables where feasible

bash

# Configuration example: update wpForo and verify version via WP-CLI
wp plugin update wpforo
wp plugin get wpforo --field=version

# Optional: temporarily deactivate wpForo until patched
wp plugin deactivate wpforo