What happened — summary for site owners and administrators

A stored Cross‑Site Scripting (XSS) vulnerability was discovered in the Colibri Page Builder plugin affecting versions up to and including 1.0.345. An authenticated user with Contributor (or higher) privileges can insert content that later renders on the front end without sufficient sanitization. Because the vector is stored, malicious script remains in the database and executes in a visitor’s browser when the affected shortcode is rendered.

• Affected software: Colibri Page Builder plugin for WordPress
• Vulnerable versions: ≤ 1.0.345
• Fixed in: 1.0.358
• CVE: CVE‑2025‑11747
• Required privilege: Contributor
• Vulnerability class: Stored Cross‑Site Scripting (XSS)
• CVSS (reported): CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L (around 6.5)

Stored XSS is often underestimated. Combined with weak session controls, privilege escalation, or social engineering, stored XSS can enable account takeover, phishing under your own domain, drive‑by malware, and content manipulation.

Why this is important — realistic impact scenarios

Stored XSS is dangerous because the attacker can persist a payload and target any user who views the affected page. Realistic outcomes include:

• Session theft or token exposure for users with elevated privileges (if cookies or tokens are not properly protected).
• Malicious redirects or UI‑spoofing to trick administrators into performing sensitive actions.
• Insertion of backdoors, JavaScript‑based malware, or content that damages SEO and reputation.
• Escalation by social engineering — attacker convinces an editor or admin to view or preview compromised content.

Because Contributor accounts (commonly used for guest writers or outside collaborators) can exploit this vector, sites that accept external content without strict review are at higher risk.

How an attacker could (theoretically) exploit this

1. Attacker registers or uses an existing Contributor account.
2. They create or edit content that includes the vulnerable shortcode or shortcode attributes processed by Colibri, embedding a script payload that is not properly sanitized.
3. The content is saved to the WordPress database.
4. When a front‑end user (visitor, editor, or admin) views the page, the stored payload runs in their browser context.
5. The payload can steal cookies, post data to an attacker, or perform actions allowed by the victim’s session and browser context.

Exploitation requires a Contributor account and user interaction (viewing or previewing the page). It is not trivially wormable across sites, but can be weaponized quickly within a single site and escalated with social engineering.

Note: No exploit code or payloads are provided here. If you are triaging this issue, do so on an isolated test instance and follow responsible disclosure practices.

Immediate actions every site owner should take (ordered)

1. Update the plugin

   Update Colibri Page Builder to version 1.0.358 or later immediately. Test the update on staging if you have complex customizations. If staging is not available, take a full backup (database + files) before updating.

2. Audit recent content and shortcodes

   Search posts, pages, widgets and postmeta for unusual shortcode patterns and suspicious attributes. Look for unexpected <script> fragments (sometimes obfuscated) or suspicious attribute values in shortcodes. Quarantine or remove content inserted by contributors you do not recognise.

3. Restrict contributor capabilities (temporary mitigation)

   Temporarily restrict Contributor role capabilities to prevent adding or editing shortcodes, or require editor review before publish. If possible, revoke external contributor access until you complete update and content audit.

4. Enable virtual patching / WAF rules

   If you operate a Web Application Firewall or use a managed security service, enable rules that detect and block the specific shortcode injection patterns. Virtual patching reduces risk for sites that cannot immediately apply the plugin update.

5. Hardening & monitoring

   Force logout of active sessions for privileged accounts after remediation. Review recent changes (user creation, post edits) and inspect server logs for suspicious activity. Increase logging on admin pages and publish/preview actions to detect exploitation attempts.

6. Clean up and recovery

   Remove malicious content from the database (posts, postmeta, options). Reset or disable vulnerable plugin shortcodes if cleaning immediately is not feasible. Revoke and reissue API keys or tokens if you suspect leakage.

How to search your site for possible malicious stored payloads (safe methods)

Use read‑only searches first — do not run automatic replacements until you have reviewed results.

Example WP‑CLI database queries (adjust table prefix if needed):

wp db query "SELECT ID, post_title, post_type FROM wp_posts WHERE post_content LIKE '%[colibri%' LIMIT 200;"

Search postmeta and options:

wp db query "SELECT meta_id, post_id, meta_key, meta_value FROM wp_postmeta WHERE meta_value LIKE '%[colibri%' LIMIT 200;"
wp db query "SELECT option_id, option_name FROM wp_options WHERE option_value LIKE '%[colibri%' LIMIT 200;"

Other guidance:

• Use the WordPress editor to search for suspected shortcode snippets and text widgets.
• Use regex‑based scanning tools to find embedded JavaScript: look for javascript:, onerror=, onload=, <script, or encoded fragments such as <script. Example search regex: (
• Be prepared for false positives; always review matches manually.

If you find malicious content, remove or sanitize it and keep an offline copy for forensic analysis.

Remediation checklist for administrators (detailed)

• Backup: Full site backup (files + DB) before remediation. Export flagged posts/pages for analysis.
• Update: Update Colibri Page Builder to 1.0.358 or later. Update WordPress core, plugins and themes while you’re at it.
• Scan and clean: Run a thorough malware scan (file system & database). Search and remove suspicious shortcodes and inline scripts. Replace or sanitize user‑supplied content that should not contain HTML/JS.
• Audit roles and users: Verify all user accounts. Disable or remove unknown users. Force password resets for Contributor and higher roles. Limit untrusted contributors until issue resolved.
• Harden editor workflow: Require editors to review contributor submissions. Consider stripping HTML from contributor submissions where possible.
• Monitoring: Enable activity logging for post create/update actions. Monitor front‑end errors and suspicious outbound requests.
• Incident response: If you detect exploitation, inform impacted users, rotate secrets (API keys, OAuth tokens), and consider professional forensic review for broader compromises.

Why a WAF (or virtual patching) matters for stored XSS

A Web Application Firewall provides an extra defensive layer while you deploy a vendor patch or perform content clean‑up. Typical WAF capabilities that help with stored XSS include:

• Virtual patching — targeted rules to block or sanitize requests and content patterns associated with the vulnerability (shortcode tokens, suspicious encodings, script fragments).
• Content scanning — automated scans to detect suspicious shortcode usage and inline script fragments in the database.
• Attack detection & alerts — notifications for administrators when likely exploitation attempts are observed.
• Least‑privilege guidance — configuration advice to limit the ability of low‑privilege users to submit shortcodes or raw HTML.

Virtual patching buys time if you cannot immediately update because of custom themes, staging limitations, or business processes. However, virtual patching is not a replacement for applying the vendor fix and cleaning stored content.

Practical example — rules and blocking approaches (conceptual)

Below are conceptual patterns for detection or blocking. These must be adapted and tuned to your environment to avoid false positives.

1. Block POST requests to admin endpoints (post.php, admin-ajax.php) that include both “[colibri” and script tokens such as “javascript:” or “onerror=”.
2. Sanitise or deny dangerous HTML tags in submissions from untrusted roles: <script>, <iframe>, <object> etc.
3. Monitor encoding tricks (e.g., <script or entity‑encoded payloads) and flag combinations of entities and suspicious tokens.

Conceptual ModSecurity‑style pseudo‑rule (illustrative only):

SecRule REQUEST_URI|ARGS_POST "@contains [colibri" "id:'900001',phase:2,deny,log,msg:'Possible Colibri shortcode XSS attempt',chain"
  SecRule REQUEST_BODY|ARGS_POST "@rx (javascript:|<script|onerror\s*=|onload\s*=|<)" "t:none"

Effective protection requires tuning and testing to avoid breaking legitimate content.

Safe triage: how to remove stored malicious content without breaking a site

1. Identify suspect content and export it first (offline copy).
2. Do not run blanket automated replacements — verify each item.
3. For posts/pages with shortcodes: edit and remove the shortcode content, replacing with a safe placeholder. If shortcode content is critical, export it and sanitize offline before reimport.
4. If many items are affected, consider disabling the plugin temporarily while cleaning.
5. After cleaning, re‑enable the plugin and test in staging before restoring to production.

Developer guidance — secure coding and hardening for shortcode handlers

• Always sanitize and escape output. Use appropriate WordPress escaping functions (esc_attr(), esc_html(), wp_kses_post(), etc.) according to context.
• Validate allowed input with whitelists for attributes and acceptable formats.
• Avoid permitting raw HTML in attributes that get rendered without escaping.
• Use nonce checks and capability checks in admin AJAX endpoints.
• Ensure only trusted roles can use shortcodes that accept HTML or scriptable content.
• Harden preview/publish workflows so potentially harmful content is reviewed before rendering to privileged users.

If you develop themes or plugins that integrate with this page builder, review your code paths to ensure untrusted content is not passed through without sanitization.

Detection guidance — what to watch for post‑remediation

• Unexpected content changes to pages or posts (especially by Contributors).
• New redirects or a spike in 404s followed by suspicious redirects.
• Browser dev tools showing outgoing requests to unknown third‑party domains when viewing pages.
• User reports of phishing or redirection after visiting site pages.
• Search engine or browser safety service warnings about malicious scripts.

If you detect signs of exploitation, take the site into maintenance mode, capture forensic snapshots, and follow recovery steps.

Hosting provider / agency checklist

• Inventory: identify all sites running the affected plugin and version.
• Prioritise: high‑traffic and admin‑heavy sites first.
• Automation: use a patch management process to push updates to staging and production after testing.
• Virtual patching: apply targeted WAF rules across affected sites to reduce exposure while updates are queued.
• Client communication: inform clients of the issue, remediation plan, and any potential service impact.
• Post‑remediation reporting: provide clients a summary of actions, findings, and recommended hardening.

Long term recommendations to reduce risk from third‑party plugins

• Maintain a plugin inventory and automated version tracking.
• Use staging for plugin updates and regression testing; avoid ad‑hoc live updates on production.
• Apply least privilege to user accounts; limit Contributor privileges where possible.
• Keep a content review process for external contributors and strip HTML from submissions if not needed.
• Remove unused plugins and themes, and perform periodic plugin audits.
• Monitor security advisories and vendor notices relevant to installed plugins.

What to do if you cannot update immediately

• Disable the plugin temporarily if it is non‑essential.
• If disabling is not possible:
  • Temporarily disable global shortcode rendering (this affects all shortcodes):

  <?php
  // Example: disable shortcode rendering globally (temporary)
  remove_filter('the_content', 'do_shortcode', 11);
  ?>

  • Restrict Contributor accounts and require editor review of all submissions.
  • Apply virtual patching rules at the WAF level to block likely exploit payloads while you prepare updates and clean content.
  • Conduct an urgent content audit and remove suspicious entries.

About responsible disclosure and CVE

This issue is tracked as CVE‑2025‑11747. When you discover similar vulnerabilities, follow responsible disclosure: notify the plugin vendor with sufficient reproduction details, avoid public exploit code until a patch is available, and coordinate disclosure to minimize harm.

Example incident timeline (how to manage an incident quickly)

1. Detection (0–1 hour): Scanner or WAF alert indicates suspicious shortcode content. Start an incident log.
2. Containment (1–3 hours): Enable WAF rules to block the pattern where possible. Restrict contributor access.
3. Investigation (3–12 hours): Identify affected pages, export suspicious content for safe review.
4. Eradication (12–48 hours): Remove malicious content, update plugin to 1.0.358, apply hardening.
5. Recovery (48–72 hours): Restore normal operations, monitor logs and user reports.
6. Lessons learned (within 1 week): Update processes, improve monitoring, and inform stakeholders.

Final recommendations — pragmatic priorities

1. Update Colibri Page Builder to 1.0.358 immediately.
2. Run a targeted content scan for shortcodes and inline scripts.
3. If you cannot update, restrict Contributor privileges and enable WAF/virtual patching.
4. Audit user accounts and sessions; force resets where appropriate.
5. Implement patching and monitoring processes to reduce future exposure windows.

If you need assistance

If you lack in‑house expertise, engage a reputable incident response or managed security provider to help with virtual patching, content cleanup, and forensic investigation. Prioritise providers with experience in WordPress incident response and database‑level remediation.