CVE-2021-38751: Exponentcms

Medium severity, CVSS 4.3. EPSS: 2.5% chance of exploitation in the next 30 days.

A HTTP Host header attack exists in ExponentCMS 2.6 and below in /exponent_constants.php. A modified HTTP header can change links on the webpage to an arbitrary value, leading to a possible attack vector for MITM.

Affected products

• Exponentcms Exponentcms: before 2.6 (fixed in 2.6)

Published 2021-08-16. Last modified 2026-06-17.