Urgent Security Advisory — SQL Injection in Profile Builder Pro (≤ 3.13.9): What WordPress Site Owners Must Do Now

Published: 25 February 2026 — This advisory summarises a high‑severity, unauthenticated SQL Injection vulnerability (CVE‑2026‑27413) affecting Profile Builder Pro versions up to and including 3.13.9. The issue permits remote SQL injection into plugin-controlled queries. CVSS score: 9.3 (High). Treat deployments using the affected versions as at immediate risk.

TL;DR (Quick actions)

• Affected: Profile Builder Pro versions ≤ 3.13.9
• Vulnerability: Unauthenticated SQL Injection — CVE‑2026‑27413
• Severity: High (CVSS 9.3)
• Immediate actions:
  1. Check plugin version; assume risk if ≤ 3.13.9.
  2. If a vendor patch exists, apply it immediately (test in staging first).
  3. If no patch is available, deactivate or remove the plugin until fixed.
  4. Enable perimeter protections (WAF/virtual patching) to block exploit attempts.
  5. Scan for Indicators of Compromise (IoCs) and review user accounts and logs.
  6. Create a full backup before further remediation.

What is SQL Injection and why it matters for WordPress

SQL Injection (SQLi) manipulates an application’s database queries by injecting crafted SQL via untrusted input. Consequences include data disclosure (user accounts, emails, hashed passwords), data modification or deletion, creation of rogue administrative accounts, and placing persistence mechanisms that lead to remote code execution. On WordPress, the database contains credentials, site configuration and plugin data — an unauthenticated SQLi like CVE‑2026‑27413 is therefore critical and requires prompt action.

Details of the Profile Builder Pro vulnerability (CVE‑2026‑27413)

• Affected software: Profile Builder Pro (plugin)
• Vulnerable versions: ≤ 3.13.9
• Vulnerability type: SQL Injection (unauthenticated)
• CVE: CVE‑2026‑27413
• CVSS score: 9.3 (High)
• Published: 23 Feb, 2026
• Report: independent security researcher (disclosure timeline by the research community)
• Patch status at disclosure: No official patch at disclosure time — verify vendor site frequently and apply updates immediately when available.

The vulnerability allows an attacker to craft HTTP requests that inject SQL into plugin-handled queries. Public advisories typically avoid publishing exact vulnerable parameter names; we also will not publish exploit parameters here. The practical result: an attacker can execute queries against your WordPress database via the plugin’s endpoints. Because this is unauthenticated, no credentials are needed to attempt exploitation.

Why exploitation is likely to be rapid

• High impact: Database access exposes PII, credentials, and potentially payment or membership data.
• Low barrier: No authentication required.
• Automation: Public disclosures are quickly turned into scanners and mass‑exploitation tools.
• Value to attackers: Many sites contain monetisable user lists or access privileges.

Assume active scanning for vulnerable installs. Prioritise remediation.

Who is at greatest risk?

• Sites with Profile Builder Pro installed and active that have not been updated.
• Membership sites or sites collecting personal data.
• WordPress Multisite networks where one plugin affects multiple sites.
• Sites lacking perimeter protections (WAF) or with limited monitoring.
• Sites without reliable backups or incident response processes.

Immediate actions for site owners (step‑by‑step, prioritised)

1. Verify plugin version

   In WordPress admin: Plugins → Installed Plugins. If Profile Builder Pro ≤ 3.13.9, assume vulnerability until the vendor issues a secure update.

2. If a patch is available, update immediately

   Apply vendor-supplied security updates. Test in staging, then push to production.

3. If no patch exists, disable the plugin

   Deactivate via WordPress admin or remove via SFTP/SSH. Note: this may disrupt login/registration flows—prepare a maintenance notice and an alternate contact channel if needed.

4. Deploy perimeter protections and virtual patching

   Enable or configure a Web Application Firewall (WAF) or similar perimeter control to block SQLi patterns and requests targeted at plugin endpoints. Block requests containing SQL metacharacters or typical payload tokens. Apply rate limits and block clearly malicious IPs. Virtual patching at the perimeter buys time while waiting for a vendor fix.

5. Run a full site scan and integrity check

   Scan for malware and unexpected file changes. Look for new PHP files in uploads, modified core/plugin/theme files, and signs of obfuscation (base64_decode, eval, gzinflate).

6. Audit users and credentials

   Review Users → All Users for unknown administrators. Reset passwords for privileged accounts. Rotate database credentials and update wp-config.php as needed if you suspect compromise.

7. Check logs and traffic

   Review web server logs and application logs for suspicious POST/GET requests to plugin endpoints and payloads containing patterns such as ‘ OR 1=1, UNION SELECT, sleep(, benchmark(, or long encoded payloads.

8. Create a backup snapshot

   Take a full backup (files + DB) before significant changes to aid forensic work or recovery.

9. Put the site into maintenance mode if necessary

   If active exploitation is suspected, temporarily take the site offline to reduce data loss while investigating.

10. If compromised, follow incident response steps (below)

Developer guidance — fixing the root cause

For developers and integrators, follow secure coding practices to prevent SQL injection:

1. Use WordPress DB APIs correctly

   Never concatenate untrusted input into SQL strings. Use $wpdb->prepare() for dynamic queries to ensure safe escaping and placeholder binding.

   global $wpdb;
   $search = $_GET['search'];
   $sql = "SELECT * FROM {$wpdb->prefix}users WHERE user_login LIKE '%" . $search . "%'";
   $rows = $wpdb->get_results($sql);

   Unsafe — do not use. Safe alternative:

   global $wpdb;
   $search = '%' . $wpdb->esc_like( sanitize_text_field( $_GET['search'] ?? '' ) ) . '%';
   $sql = $wpdb->prepare(
       "SELECT * FROM {$wpdb->users} WHERE user_login LIKE %s",
       $search
   );
   $rows = $wpdb->get_results( $sql );

2. Prefer $wpdb helper methods

   Use $wpdb->insert(), $wpdb->update(), and $wpdb->delete() for DML operations — they handle escaping.

3. Validate and sanitize input

   Use sanitize_text_field(), intval(), floatval(), wp_kses_post() as appropriate. Enforce length limits and patterns and reject unexpected input early.

4. Prepared statements for IN clauses

   Create placeholders for dynamic IN lists and pass values to $wpdb->prepare(). If the array is empty, skip the query.

   $ids = array_map( 'intval', $ids_array ); // ensure integers
   $placeholders = implode( ',', array_fill( 0, count( $ids ), '%d' ) );
   $sql = $wpdb->prepare( "SELECT * FROM {$wpdb->posts} WHERE ID IN ($placeholders)", $ids );

5. Enforce capability checks and nonces

   Use current_user_can() for privileged actions and verify nonces (wp_verify_nonce()) for authenticated endpoints. Public endpoints must limit exposed data and sanitize strictly.

6. Do not leak raw DB errors

   Detailed SQL errors can reveal schema details to attackers. Log errors securely but return generic messages to callers.

7. Test with fuzzing and scanners

   Include automated tests that simulate injection attempts to ensure prepared statements and sanitisation are effective.

Indicators of Compromise (IoCs) — check immediately

• New admin users you did not create
• Unexpected changes to wp_options (siteurl, home, active_plugins)
• Unknown PHP files in wp-content/uploads or other writeable directories
• Modified theme/plugin files with obfuscated code (base64_decode, eval, gzinflate)
• Database logs showing UNION, information_schema queries, or unusual SELECTs
• Cron jobs or scheduled tasks you did not create
• Unusual outbound connections from the server
• Sudden spikes in DB CPU usage or slow queries

If any IoCs are present, assume compromise until proven otherwise.

Incident response playbook (if you detect a compromise)

1. Isolate

   Place the site in maintenance mode or take it offline. Block malicious IPs and traffic to vulnerable endpoints.

2. Preserve evidence

   Take full backups (files + DB) before changes. Preserve logs and timestamps. If engaging forensics, retain read‑only copies.

3. Identify and contain

   Find backdoors, changed files and unauthorized accounts. Quarantine affected components.

4. Eradicate

   Remove the vulnerable plugin or apply code fixes. Replace modified files with clean versions. Rotate all credentials (admin, DB, API keys, hosting panels, SSH).

5. Recover

   Restore from a known clean backup if necessary. Harden the site: enforce least privilege, tighten file permissions, improve monitoring.

6. Post‑incident review

   Analyse attack vector, close gaps, update playbooks, and schedule follow‑up audits.

7. Notify stakeholders

   If personal data was exposed, follow legal notification requirements for your jurisdiction.

Testing mitigations safely

• Never test exploit payloads on production.
• Use a staging environment that mirrors production for WAF rules and plugin removal tests.
• Monitor for false positives — overly broad blocking can disrupt legitimate services. Whitelist trusted IPs or endpoints after review.
• Keep logs of blocked requests to refine rules without impacting users.

Long‑term hardening recommendations

• Keep WordPress core, themes and plugins updated; schedule regular checks.
• Use a WAF for perimeter protection and virtual patching for zero‑day risks.
• Enforce least privilege for the DB user; avoid excessive rights (DROP, GRANT).
• Require strong, unique passwords and two‑factor authentication for admin accounts.
• Maintain offsite immutable backups (30+ days) and regularly test restores.
• Perform scheduled security audits and code reviews for custom code.
• Centralise logging (web, app, DB) and set alerts for anomalous behaviour.
• Deploy file integrity monitoring to detect unexpected changes.

Practical checklist you can use now

• Check if Profile Builder Pro is installed and confirm its version.
• If version ≤ 3.13.9 and no patch exists, deactivate or remove the plugin immediately.
• Enable a WAF or perimeter rules to block SQL injection patterns.
• Create a full backup (files + DB).
• Run malware and file‑integrity scans.
• Audit users and reset admin passwords.
• Review logs for suspicious requests and IoCs.
• If a compromise is suspected, follow the incident response playbook and engage professional help if you lack in‑house capability.

Closing thoughts

Unauthenticated SQL Injection is among the most damaging vulnerabilities because it targets your data layer directly. Treat installs of Profile Builder Pro ≤ 3.13.9 as high priority: verify versions, apply vendor updates when available, enable perimeter protections, scan for compromise, and follow incident response procedures if you observe suspicious activity. Quick, decisive action reduces data loss and reputational damage.

— Hong Kong Security Expert