# CVE-2026-111830: WP Mailster stored cross-site scripting

Source: https://junglewise.ai/threats/cve-2026-111830-improper-neutralization-of-input-during-web-page-generation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-22. Updated: 2026-10-22  
License: CC BY 4.0 with a link back

CVE-2026-111830 · Severity: high · CVSS 7.1 · Published 2026-10-22

WP Mailster is a WordPress plugin for email marketing that allows site administrators and users to create and manage email campaigns. A stored cross-site scripting (XSS) vulnerability allows attackers to inject malicious scripts into the plugin that affect site visitors, potentially stealing their data or hijacking their accounts. The vulnerability requires an authenticated user or admin to be tricked into clicking a malicious link or visiting a crafted page.

Technologies: [WP Mailster](https://junglewise.ai/threats/technologies/wp-mailster). Vendors: [WP Mailster](https://junglewise.ai/threats/vendors/wp-mailster).

## Quick answers

**Is CVE-2026-111830 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111830 being exploited in the wild.

**How severe is CVE-2026-111830?** High severity, with a CVSS score of 7.1, published 22 October 2026.

**Which products and versions are affected?** WP Mailster through 1.9.1.0.

**Is there a fix for CVE-2026-111830?** Yes: fixed in 1.9.2.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-111830 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-111830?** Check whether you run WP Mailster 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 1.9.2.0

## Technical details

A stored cross-site scripting vulnerability in WP Mailster allows improper neutralization of user input during web page generation. An unauthenticated attacker can inject malicious scripts that persist in the application and are executed in the browsers of other users, including administrators. Exploitation requires user interaction from a privileged user.

## Affected products

- WP Mailster WP Mailster through 1.9.1.0

## Timeline

- 2026-10-20: disclosed
- 2026-10-22: advisory

## References

- [https://wordpress.org/plugins](https://wordpress.org/plugins)
- [https://patchstack.com/database/wordpress/plugin/wp-mailster/vulnerability/wordpress-wp-mailster-plugin-1-9-1-0-cross-site-scripting-xss-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/wp-mailster/vulnerability/wordpress-wp-mailster-plugin-1-9-1-0-cross-site-scripting-xss-vulnerability?_s_id=cve)

## Related threats

- [WP Mailster arbitrary file upload vulnerability](https://junglewise.ai/threats/cve-2026-111832-unrestricted-upload-of-file-with-dangerous-type-vulnerability-in)
- [WP Mailster local file inclusion vulnerability](https://junglewise.ai/threats/cve-2026-111829-improper-control-of-filename-for-include-require-statement-in)
- [WP Mailster cross-site scripting (XSS) vulnerability](https://junglewise.ai/threats/cve-2026-105061-unauthenticated-cross-site-scripting-xss-in-wp-mailster-1-9-0-0)
- [WP Mailster broken access control vulnerability](https://junglewise.ai/threats/cve-2026-105055-missing-authorization-vulnerability-in-wp-mailster-wp-mailster)