# CVE-2026-93766: Happyforms Pro stored cross-site scripting in referral link

Source: https://junglewise.ai/threats/cve-2026-93766-the-happyforms-pro-plugin-for-wordpress-is-vulnerable-to-stored  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-07. Updated: 2026-11-07  
License: CC BY 4.0 with a link back

CVE-2026-93766 · Severity: high · CVSS 7.2 · Published 2026-11-07

Happyforms Pro is a WordPress form builder plugin used to create contact forms, surveys, and payment forms. The plugin fails to properly sanitize the referral link parameter, allowing unauthenticated attackers to inject malicious JavaScript that executes in the browsers of users viewing affected forms. This could lead to credential theft, session hijacking, or spreading malware to site visitors.

Vendors: [Happyforms](https://junglewise.ai/threats/vendors/happyforms).

## Quick answers

**Is CVE-2026-93766 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-93766 being exploited in the wild.

**How severe is CVE-2026-93766?** High severity, with a CVSS score of 7.2, published 7 November 2026.

**Which products and versions are affected?** Happyforms Pro up to and including 1.38.9.

**Is there a fix for CVE-2026-93766?** Yes: fixed in 1.38.10. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-93766 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-93766?** Check whether you run Happyforms Pro 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.

## How to fix

- Fixed in 1.38.10

## Technical details

The 'happyforms_client_referer' parameter is vulnerable to stored cross-site scripting (XSS) due to insufficient input sanitization and output escaping. An unauthenticated attacker can inject arbitrary JavaScript through this parameter, which persists in the form and executes whenever a user accesses an affected page. The vulnerability was fixed in version 1.38.10 released on November 5, 2026.

## Affected products

- Happyforms Happyforms Pro up to and including 1.38.9

## Timeline

- 2026-11-07: disclosed: CVE-2026-93766 published
- 2026-11-05: patched: Fixed in version 1.38.10

## References

- [https://happyforms.io/whats-new/](https://happyforms.io/whats-new/)
- [https://wordpress.org/plugins/happyforms-upgrade/](https://wordpress.org/plugins/happyforms-upgrade/)