The Microtango plugin permits authenticated WordPress users with Contributor or higher privileges to inject arbitrary scripts into pages through the unsanitized ‘restkey’ parameter of the mt_reservation shortcode. Injected scripts are stored and executed in the browser context of any visitor to the affected page, enabling attacks that compromise confidentiality, integrity, and availability of site content. The weakness is a classic input validation failure classified as CWE‑79.

All releases of Microtango up to and including version 0.9.29 that feature the mt_reservation shortcode. The plugin is distributed through WordPress.org and used by any WordPress installation that incorporates the affected plugin.

The vulnerability carries a CVSS score of 6.4, indicating moderate severity. The EPSS score is reported as less than 1 %, suggesting a low but non-zero likelihood of exploitation, and the issue is not listed in the CISA KEV catalog. Because the attack requires only authenticated Contributor‑level access, a relatively broad set of users can exploit it; however the stored nature of the XSS means that any subsequent reviewer of the affected page will experience arbitrary script execution. Exporting or re‑deploying the site without remediation does not mitigate the risk; the only reliable defense is to update or disable the affected functionality.