Concrete CMS 9.5.0 and below is vulnerable to IDOR in the`/ccm/frontend/conversations/message_detail` endpoint
33Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 6.3epss 0.2%
from disclosure to weapon72 days
Published on NVDMay 21
1st PoC+72d
exploitation probability
0.2%top 90% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
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, including messages from restricted pages, member-only areas, and the moderation queue. File attachments with download URLs are also exposed. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Eldudareeno for reporting.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
Concrete CMS · Concrete CMSpublic PoCs found — 1
githubgithub.com/aj2108/CVE-2026-8237★ 0⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.