CVE-2026-91073: Unknown Subscribe Forms

Medium severity, CVSS 6.8. EPSS: 0.2% chance of exploitation in the next 30 days.

The Subscribe Forms WordPress plugin before 1.6.3 does not sanitise and escape one of its form settings before outputting it in a page, allowing authenticated users with the Author role and above to perform Stored Cross-Site Scripting attacks that execute in the browser of any visitor who views a page embedding the form, including logged-out visitors and administrators.

Affected products

• Unknown Subscribe Forms: from 1.4.1, before 1.6.3 (fixed in 1.6.3)

Published 2026-09-23. Last modified 2026-09-23.