CVE-2021-40106: Concretecms Concrete CMS

Medium severity, CVSS 6.1. EPSS: 0.7% chance of exploitation in the next 30 days.

An issue was discovered in Concrete CMS through 8.5.5. There is unauthenticated stored XSS in blog comments via the website field.

Affected products

• Concretecms Concrete CMS: up to and including 8.5.5

Published 2021-09-27. Last modified 2026-06-17.