CVE-2026-14558: Unknown User Frontend

High severity, CVSS 7.2. EPSS: 0.5% chance of exploitation in the next 30 days.

The User Frontend WordPress plugin before 4.3.10 does not properly validate field type definitions and deserialises user-controlled post metadata when rendering submitted posts, allowing users with Editor-level access and above to inject arbitrary PHP objects, which can lead to remote code execution when a suitable POP chain is present on the site.

Affected products

• Unknown User Frontend: before 4.3.10 (fixed in 4.3.10)

Published 2026-08-28. Last modified 2026-08-28.