# CVE-2026-105881: ThemeGrill User Registration stored cross-site scripting

Source: https://junglewise.ai/threats/cve-2026-105881-improper-neutralization-of-input-during-web-page-generation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-105881 · Severity: medium · CVSS 6.5 · Published 2026-10-13

ThemeGrill User Registration is a WordPress plugin that allows website visitors to create accounts and register with a site. A stored cross-site scripting vulnerability in versions up to 5.2.8 allows a contributor or developer-level user to inject malicious scripts that persist in the site and can steal visitor data or hijack visitor accounts when those scripts execute in other users' browsers.

Technologies: [ThemeGrill User Registration](https://junglewise.ai/threats/technologies/themegrill-user-registration). Vendors: [ThemeGrill](https://junglewise.ai/threats/vendors/themegrill).

## Quick answers

**Is CVE-2026-105881 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105881 being exploited in the wild.

**How severe is CVE-2026-105881?** Medium severity, with a CVSS score of 6.5, published 13 October 2026.

**Which products and versions are affected?** ThemeGrill User Registration through 5.2.8.

**Is there a fix for CVE-2026-105881?** Yes: fixed in 5.3.0. Until then: Update to version 5.3.0 or later immediately. If unable to update, restrict contributor and developer role permissions until patching is possible. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-105881 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-105881?** Check whether you run ThemeGrill User Registration 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 5.3.0

Update to version 5.3.0 or later immediately. If unable to update, restrict contributor and developer role permissions until patching is possible.

## Technical details

The plugin fails to properly neutralize user-supplied input during web page generation, allowing authenticated attackers with contributor or developer roles to inject persistent JavaScript code. The vulnerability is stored, meaning the malicious script remains in the database and executes whenever the affected page is viewed. Exploitation requires user interaction in the form of a privileged user submitting or clicking on malicious input.

## Affected products

- ThemeGrill User Registration through 5.2.8

## Timeline

- 2026-09-26: disclosed
- 2026-10-13: advisory

## References

- [https://wordpress.org/plugins](https://wordpress.org/plugins)
- [https://patchstack.com/database/wordpress/plugin/user-registration/vulnerability/wordpress-user-registration-plugin-5-2-8-cross-site-scripting-xss-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/user-registration/vulnerability/wordpress-user-registration-plugin-5-2-8-cross-site-scripting-xss-vulnerability?_s_id=cve)

## Related threats

- [ThemeGrill User Registration broken access control](https://junglewise.ai/threats/cve-2026-124258-missing-authorization-vulnerability-in-themegrill-user)
- [ThemeGrill User Registration broken access control](https://junglewise.ai/threats/cve-2026-119522-missing-authorization-vulnerability-in-themegrill-user)
- [ThemeGrill User Registration missing authorization](https://junglewise.ai/threats/cve-2026-120840-missing-authorization-vulnerability-in-themegrill-user)
- [ThemeGrill User Registration Cross Site Scripting](https://junglewise.ai/threats/cve-2026-27061-subscriber-cross-site-scripting-xss-in-user-registration-5-3-0)
- [ThemeGrill User Registration broken access control](https://junglewise.ai/threats/cve-2026-25450-missing-authorization-vulnerability-in-themegrill-user)