CVE-2026-52630: Woltlab WCF SQL Injection Vulnerability

CVE-2026-52630 Overview

CVE-2026-52630 is a SQL injection vulnerability [CWE-89] in WoltLab WCF (Community Framework) version 6.2.4 and earlier. The flaw resides in the updateUserOptions method in UserEditor.class.php and the update action in UserAction.class.php. A remote, unauthenticated attacker can inject arbitrary SQL statements through user option handling. Successful exploitation compromises database confidentiality, integrity, and availability. WoltLab addressed the issue in WoltLab Suite versions 6.2.5, 6.1.22, 6.0.26, and 5.5.26.

Critical Impact
Remote attackers can execute arbitrary SQL queries against the WoltLab Suite database without authentication, enabling full data exfiltration, forum takeover, and privilege escalation to administrative accounts.

Affected Products

WoltLab WCF (WoltLab Community Framework) version 6.2.4 and earlier
WoltLab Suite 6.1.x prior to 6.1.22
WoltLab Suite 6.0.x prior to 6.0.26 and 5.5.x prior to 5.5.26

Discovery Timeline

2026-09-11 - CVE-2026-52630 published to NVD
2026-09-14 - Last updated in NVD database

Technical Details for CVE-2026-52630

Vulnerability Analysis

The vulnerability is a classic SQL injection [CWE-89] in the user management pipeline of WoltLab WCF. Two code paths accept attacker-controlled input that reaches SQL statements without proper parameterization. The updateUserOptions routine in UserEditor.class.php processes user option keys and values before persisting them. The update action in UserAction.class.php exposes the same code path over the framework's action dispatch API, which is reachable remotely.

Because the injection point sits inside a write operation, an attacker can both read and modify database contents. In a typical WoltLab Suite deployment this includes session tokens, password hashes, private messages, and administrative option tables. The remote attacker requires no authentication and no user interaction.

Root Cause

The root cause is improper neutralization of special elements used in SQL commands. User-supplied option identifiers or values are concatenated into query fragments rather than bound as prepared statement parameters. Any input reaching the vulnerable routines is trusted for SQL context, allowing statement termination and injection of arbitrary clauses.

Attack Vector

Exploitation occurs over the network by sending a crafted request to the WoltLab action endpoint that invokes the update action of UserAction. The attacker supplies a payload in the user options structure that breaks out of the intended SQL context. Because the flaw is exposed through the standard AJAX action controller, no plugins or non-default configurations are required.

No public proof-of-concept exploit is currently available. Technical details are referenced in the WoltLab WCF Repository and the WoltLab Suite Update Thread.

Detection Methods for CVE-2026-52630

Indicators of Compromise

HTTP POST requests to the WoltLab action controller invoking UserAction with actionName=update and payloads containing SQL metacharacters such as single quotes, UNION, SELECT, SLEEP(, or -- inside the data[options] structure.
Web server access logs showing repeated requests to index.php?ajax-proxy/ or core/ajax-proxy with unusually large or encoded option parameters.
Unexpected new administrator accounts, altered user group assignments, or modified rows in wcf1_user_option_value and wcf1_user tables.
Database error entries in PHP or MySQL logs referencing malformed statements originating from UserEditor::updateUserOptions.

Detection Strategies

Deploy Web Application Firewall (WAF) signatures that inspect action controller POST bodies for SQL injection patterns targeting the data[options] field.
Enable MySQL general query logging on staging or high-value production instances to identify anomalous queries against wcf1_user* tables that include attacker-controlled clauses.
Correlate outbound requests from the web server with inbound requests to UserAction/update to detect data exfiltration attempts leveraging blind SQLi.

Monitoring Recommendations

Alert on any modification to WoltLab administrator group membership or on new sessions issued to accounts that have not recently authenticated interactively.
Monitor for CPU or query-time spikes on the WoltLab database consistent with time-based blind SQL injection probing.
Track requests to the ajax-proxy endpoint by source IP and rate-limit anomalous volumes.

How to Mitigate CVE-2026-52630

Immediate Actions Required

Upgrade WoltLab Suite to 6.2.5, 6.1.22, 6.0.26, or 5.5.26 depending on the deployed branch. See the WoltLab Suite Update Thread.
Rotate all administrator passwords, API keys, and session secrets on affected installations, as pre-patch exploitation cannot be ruled out.
Audit the wcf1_user, wcf1_user_group, and wcf1_user_option_value tables for unauthorized modifications.

Patch Information

WoltLab published fixed releases 6.2.5, 6.1.22, 6.0.26, and 5.5.26 addressing the SQL injection in UserEditor::updateUserOptions and the update action of UserAction. Administrators should apply the update via the built-in package system or by deploying the corresponding release from the WoltLab WCF Repository.

Workarounds

Restrict access to the WoltLab administrative and AJAX endpoints to trusted IP ranges using reverse proxy or firewall rules until patching is complete.
Deploy WAF rules that block requests to the action controller containing SQL metacharacters in the user options payload.
Temporarily disable public registration and user profile editing to reduce the attack surface exposed through the UserAction endpoint.

bash

# Example nginx rule blocking suspicious UserAction/update payloads
location ~ ^/(index\.php|core/ajax-proxy) {
    if ($request_body ~* "actionName=update.*className=.*UserAction.*(union|select|sleep\(|--|/\*)") {
        return 403;
    }
    include fastcgi_params;
    fastcgi_pass php-fpm;
}