# CVE-2026-105055: WP Mailster broken access control vulnerability

Source: https://junglewise.ai/threats/cve-2026-105055-missing-authorization-vulnerability-in-wp-mailster-wp-mailster  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-05. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-105055 · Severity: medium · CVSS 5.3 · Published 2026-10-05

WP Mailster is a WordPress plugin for email marketing campaigns. A broken access control vulnerability allows authenticated users with the Contributor role to access pages and perform actions they should not be permitted to, such as viewing other users' data or performing administrative functions.

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

## Quick answers

**Is CVE-2026-105055 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105055 being exploited in the wild.

**How severe is CVE-2026-105055?** Medium severity, with a CVSS score of 5.3, published 5 October 2026.

**Which products and versions are affected?** WP Mailster through 1.9.0.0.

**Is there a fix for CVE-2026-105055?** Yes: fixed in 1.9.1.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-105055 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-105055?** 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 1.9.1.0

## Technical details

The plugin fails to properly enforce authorization checks on certain functions, allowing users with lower privilege levels (Contributor role or above) to access restricted functionality. The vulnerability requires authentication and user interaction to exploit. A fix is available in version 1.9.1.0.

## Affected products

- WP Mailster WP Mailster through 1.9.0.0

## Timeline

- 2026-09-22: disclosed: Reported by Ratchanon Chamnankit
- 2026-10-05: advisory: Published by Patchstack

## References

- [https://wordpress.org/plugins](https://wordpress.org/plugins)
- [https://patchstack.com/database/wordpress/plugin/wp-mailster/vulnerability/wordpress-wp-mailster-plugin-1-9-0-0-broken-access-control-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/wp-mailster/vulnerability/wordpress-wp-mailster-plugin-1-9-0-0-broken-access-control-vulnerability?_s_id=cve)

## Related threats

- [WP Mailster stored cross-site scripting](https://junglewise.ai/threats/cve-2026-111830-improper-neutralization-of-input-during-web-page-generation)
- [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)