# CVE-2026-16787: Live Composer stored cross-site scripting in custom field shortcode

Source: https://junglewise.ai/threats/cve-2026-16787-live-composer-stored-cross-site-scripting-in-custom-field  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-01. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-16787 · Severity: medium · CVSS 6.4 · Published 2026-09-01

The Live Composer WordPress plugin is a popular website building tool used by non-technical site administrators to create and manage web pages. The plugin fails to properly sanitize user input in custom field shortcodes, allowing authenticated contributors to inject malicious scripts that execute when other users view affected pages. This could enable account takeover, defacement, or malware distribution to site visitors.

Technologies: [Live Composer Free WordPress Website Builder](https://junglewise.ai/threats/technologies/free-wordpress-website-builder). Vendors: [Live Composer](https://junglewise.ai/threats/vendors/live-composer).

## Quick answers

**Is CVE-2026-16787 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-16787 being exploited in the wild.

**How severe is CVE-2026-16787?** Medium severity, with a CVSS score of 6.4, published 1 September 2026.

**Which products and versions are affected?** Live Composer Free WordPress Website Builder up to 2.1.19.

**Is there a fix for CVE-2026-16787?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-16787 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-16787?** Check whether you run Live Composer Free WordPress Website Builder at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a stored cross-site scripting (XSS) flaw in the 'dslc_custom_field' shortcode handler, resulting from insufficient input sanitization and output escaping. An authenticated attacker with contributor-level or higher permissions can inject arbitrary JavaScript code into shortcode parameters; the unescaped payload is stored in the database and executed in the browsers of all users who view the affected page. The attack requires existing authentication but no further user interaction. Patches are available in versions after 2.1.19.

## Affected products

- Live Composer Free WordPress Website Builder up to 2.1.19

## Timeline

- 2026-09-01: disclosed

## References

- [https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/includes/shortcodes.php](https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/includes/shortcodes.php)
- [https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/includes/shortcodes.php](https://plugins.trac.wordpress.org/browser/live-composer-page-builder/tags/2.1.18/includes/shortcodes.php)

## Related threats

- [Live Composer stored cross-site scripting in downloads shortcode](https://junglewise.ai/threats/cve-2026-16778-the-live-composer-free-wordpress-website-builder-plugin-for)
- [Live Composer stored cross-site scripting via dslc_module_projects shortcode](https://junglewise.ai/threats/cve-2026-16788-live-composer-stored-cross-site-scripting-via-dslc-module)
- [Live Composer Free WordPress Website Builder stored XSS in custom_id shortcode attribute](https://junglewise.ai/threats/cve-2026-13203-live-composer-free-wordpress-website-builder-stored-xss-in-custom)