Urgent Security Advisory — CVE-2026-2495: Unauthenticated SQL Injection in WPNakama (≤ 0.6.5)

Author: Hong Kong Security Expert • Date: 2026-02-18

Summary: A high severity SQL injection vulnerability (CVE-2026-2495, CVSS 9.3) was disclosed for the WordPress plugin WPNakama affecting versions ≤ 0.6.5. The flaw allows unauthenticated actors to manipulate a REST API parameter named order, resulting in SQL injection against the plugin’s database queries. This advisory explains the risk, realistic attack paths, detection and incident response guidance, and practical mitigations. If you manage WordPress sites, act immediately — the vulnerability is trivial to exploit and can lead to database exposure.

Background: what was disclosed

On 18 February 2026 a high severity vulnerability was publicly disclosed for the WordPress plugin WPNakama (versions ≤ 0.6.5). The vulnerability is assigned CVE-2026-2495 and is classified as an unauthenticated SQL injection via a REST API parameter named order. A fixed release (0.6.6) is available that addresses the issue.

Key facts at a glance:

• Affected software: WPNakama plugin for WordPress
• Vulnerable versions: ≤ 0.6.5
• Fixed in: 0.6.6
• Vulnerability type: SQL Injection via REST API order parameter
• Access required: Unauthenticated (public)
• CVSS (indicative): 9.3 — High severity
• Impact: Potential database reading and disclosure, data exfiltration, and partial site compromise

Why SQL injection matters (short)

SQL injection remains one of the most dangerous web vulnerability classes. Successful SQLi allows attackers to execute arbitrary database queries through application inputs. For WordPress sites, consequences can include:

• Exposure of sensitive data: user emails, password hashes (if stored), order history, and other PII.
• Account takeover or escalation: attackers may create or modify administrator records.
• Persistent backdoors: implantation of code or creation of malicious admin users.
• Data deletion or tampering: impacting availability and integrity.

This issue is worsened by being exploitable without authentication and via a public REST endpoint — making it attractive to scanners and opportunistic attackers.

Technical root cause (what went wrong in the plugin)

From available disclosure details and common patterns, the core problem is clear:

• A REST API endpoint exposed by the plugin accepts a parameter named order and uses it to build SQL queries that fetch orders or related records.
• Input from order is concatenated or interpolated directly into an SQL statement without proper validation, sanitization, or parameterization.
• The plugin likely did not use $wpdb->prepare() or prepared statements for dynamic SQL fragments, or it allowed unsafely-cast values in SQL fragments (e.g., ORDER BY, WHERE).

Typical vulnerable pattern examples include:

$sql = "SELECT * FROM {$table} WHERE status = 'complete' ORDER BY " . $order;

Because REST endpoints are often query-string based and publicly exposed, an attacker can craft a URL like:

/wp-json/wpnakama/v1/orders?order=<payload>

Note: exploit details and proofs-of-concept are intentionally omitted to avoid enabling malicious actors. Guidance below focuses on defensive actions.

Exploitation scenarios — realistic attacker goals

An unauthenticated SQLi on an order-related endpoint allows several attacker objectives:

1. Data theft — extract orders, customer billing information, and PII.
2. User enumeration and credential exposure — retrieve user records and password-related metadata.
3. Account takeover — insert or modify user records to create privileged accounts.
4. Site persistence/backdoors — plant malicious options or posts enabling remote code execution via other chains.
5. Lateral movement and monetization — sell exfiltrated data or install malicious plugins/themes.

Because the endpoint is public, automated scanners and mass-exploitation scripts will likely appear quickly after disclosure. Treat public-facing sites using the plugin as at-risk until patched.

Immediate mitigations you can apply (prioritized)

If you run WordPress sites using WPNakama, act immediately. Follow this prioritized list:

1. Update the plugin (preferred)
   • Update WPNakama to version 0.6.6 or later immediately. This is the only permanent fix for the vulnerability.
   • For fleets, schedule a high-priority bulk update and verify success across sites.
2. If you cannot update immediately — block the vulnerable endpoint
   • Block access to the plugin REST route temporarily at the webserver or edge level (see examples below).
   • At minimum, deny public access to /wp-json/wpnakama/ until the plugin is updated.
3. Disable the plugin until patched
   • If you cannot block the endpoint, disable WPNakama entirely until an update is applied.
4. Deploy virtual patching / WAF rules where available
   • Deploy WAF signatures that target SQL injection in the order parameter for the plugin’s endpoints. See the WAF section for rule ideas.
5. Monitor logs for exploitation indicators
   • Check web access logs for requests to /wp-json/wpnakama/ and suspicious order= payloads.
   • Review database activity for unexpected SELECTs or data exports.
6. Apply least-privilege where feasible
   • Ensure WordPress database credentials do not have excessive privileges where possible.

WAF and virtual-patching recommendations (practical rules)

When rapid updates across many sites are required, virtual patching with a WAF can buy critical time. Below are practical signatures and strategies — tune and test to avoid false positives.

High-level rule logic

• Block public requests to REST endpoints associated with the plugin:
  • URI pattern: ^/wp-json/wpnakama/.*$
• Detect SQL injection payloads in order parameter:
  • Look for SQL keywords (case-insensitive) in parameter values: UNION, SELECT, SLEEP, BENCHMARK, INFORMATION_SCHEMA, LOAD_FILE, INTO OUTFILE
  • Detect SQLi characters/sequences: ' OR '1'='1, --, /*, */, ;, #
  • Time-based functions used in fingerprinting: SLEEP(), BENCHMARK(), pg_sleep()

Conceptual ModSecurity-style example (adapt to your WAF):

SecRule REQUEST_URI "@pm /wp-json/wpnakama/ /wp-json/wpnakama/v1/" \
 "id:100001,phase:1,deny,log,msg:'Block WPNakama REST endpoint access - temporary mitigation'"

SecRule ARGS:order "@rx (?:\bUNION\b|\bSELECT\b|\bSLEEP\(|\bBENCHMARK\(|--|;|/\*|\*/|#)" \
 "id:100002,phase:2,deny,log,msg:'SQLi attempt in WPNakama order parameter'"

Server-level blocking examples

nginx:

location ~ ^/wp-json/wpnakama/ {
    return 403;
}

Apache (.htaccess):

  Require all denied

These measures block the entire plugin API endpoint — acceptable as a short-term mitigation if updates cannot be applied immediately. Alternative approaches include rate-limiting, blocking anonymous clients, or requiring an emergency authentication header for the path.

Detection and incident response checklist

If you suspect probing or exploitation, treat systems as potentially compromised and follow this checklist.

1. Preserve evidence
   • Do not restart servers or delete logs. Collect web and database logs for analysis.
   • Create filesystem snapshots if possible for forensic review.
2. Search web-access logs
   • Look for requests to /wp-json/wpnakama/ and any order= occurrences.
   • Identify requests containing SQL keywords (UNION, SELECT, SLEEP, etc.) and note source IPs and user agents.
3. Inspect the database
   • Check wp_users and wp_usermeta for new or modified administrator accounts.
   • Search wp_options and wp_posts for unexpected values or injected content.
4. Malware scan
   • Use multiple trusted scanning tools to look for webshells, modified core files, or persistence mechanisms.
   • Check common persistence locations: wp-content/uploads, mu-plugins, themes and plugins directories.
5. Rotate credentials
   • Reset administrator passwords and any API keys that may have been exposed.
   • Rotate database credentials if you suspect credential exposure or misuse.
6. Restore from clean backup if necessary
   • If persistent backdoors or unauthorized admin accounts are found, restore from a pre-compromise backup and then patch the plugin.
7. Notify stakeholders and follow legal obligations
   • If personal data was exposed, follow applicable notification and compliance procedures.
8. Consider professional forensic support
   • For high-value or e-commerce sites, engage a professional incident response team for a thorough investigation.

Hardening and longer-term fixes (for plugin authors and site owners)

For plugin developers (proper fixes)

• Never trust user input — validate and sanitize fields that will be used in SQL queries.
• Use $wpdb->prepare() for queries with dynamic values.
• For ORDER BY or column selection, whitelist allowed columns and map user-supplied values to safe identifiers:

  $allowed = ['date', 'total', 'status'];
  $order = in_array($request_order, $allowed, true) ? $request_order : 'date';

• Avoid inserting raw user input into SQL fragments; if unavoidable, strictly validate against expected types/values.
• Use REST API permission callbacks to restrict access to endpoints that expose sensitive data. If an endpoint must be public, enforce strict input validation.

For site owners (preventive hardening)

• Keep WordPress core, themes, and plugins up to date and apply security patches quickly.
• Limit attack surface:
  • Disable unused plugins and remove unneeded REST endpoints where feasible.
  • Consider restricting the WordPress REST API to authenticated users if possible.
• Enforce least-privilege user roles and regularly audit admin accounts.
• Use a reliable backup solution and verify restore procedures periodically.

Practical restoration and recovery plan (step-by-step)

If a compromise is confirmed, follow this ordered playbook:

1. Triage and isolate
   • Put the site in maintenance mode and restrict public access (temporary HTTP auth if needed).
2. Back up current state (evidence)
   • Export webserver and database logs and archive current site files for forensic review.
3. Patch and remove the vulnerability
   • Update WPNakama to 0.6.6 or remove the plugin if not required.
4. Clean infected files
   • Replace WordPress core and plugin files with known-good copies. Remove unknown PHP files or suspicious code; when in doubt, restore from a clean backup.
5. Reset access
   • Reset admin passwords and reissue any compromised API credentials.
6. Strengthen defenses
   • Deploy WAF rules, apply strict input validation in custom code, and enable auto-updates for critical patches where safe.
7. Post-mortem and monitoring
   • Run a full audit to confirm no residual persistence and monitor logs closely for 30 days.
8. Communicate
   • Inform stakeholders and customers as required by your incident response plan and legal obligations.

Appendix: useful quick-reference commands and log patterns

Search for suspicious REST requests (Linux shell):

# web access logs (nginx example)
sudo zgrep -i "wp-json/wpnakama" /var/log/nginx/access*.log*
sudo zgrep -i "order=" /var/log/nginx/access*.log*

Common log patterns and red flags:

• Requests with order= containing SQL keywords (e.g., order=union, order=select, order=sleep().
• Many requests from the same IP trying different payloads rapidly.
• Requests with SQL comment sequences: --, /*, */, #.
• Requests with suspicious user-agents or non-browser clients.

Database queries to inspect (high-level):

SELECT ID, user_login, user_email, user_registered FROM wp_users WHERE user_registered >= '2026-02-01';

Also check wp_options for unexpected autoloaded values and unusual entries in wp_posts.

Final notes — be proactive, not reactive

This vulnerability is a reminder that plugins can introduce severe risks when user input is not handled safely, particularly on publicly exposed REST endpoints. The fastest, most reliable remediation is to apply the fix (update to 0.6.6). For environments where immediate updates are impractical (large fleets, change-control windows, custom integrations), virtual patching via WAF combined with endpoint blocking and careful monitoring is a practical stopgap.

Two recommended immediate actions for administrators:

1. Update all WPNakama installations to 0.6.6 or disable the plugin immediately.
2. If updates cannot be applied immediately, block the plugin’s REST endpoint (/wp-json/wpnakama/) at the edge or webserver and monitor logs for suspicious activity.