Auth bypass in Concrete Cms
CVE-2026-8237
Concrete CMS 9.5.0 and below is vulnerable to IDOR. The `/ccm/frontend/conversations/message_detail` endpoint returns the full content of any conversation message. An unauthenticated attacker can enumerate all conversation messages, includ…
Vulnerability class: Broken Access Control
EPSS: 0.000 (14.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Concrete Cms — versions 5.0
- Concretecms Concrete_cms
Weakness classification (CWE)
References
- ff5b8ace-8b95-4078-9743-eac1ca5451de (release-notes, Release Notes)
Frequently asked questions
- What is CVE-2026-8237?
- CVE-2026-8237 is a medium-severity vulnerability in Concrete Cms, classified under Missing Authorization. CVSS score: 5.3/10. Published 2026-05-21.
- How severe is CVE-2026-8237?
- Medium severity. CVSS v3 base score is 5.3 out of 10.