CVE-2026-8238 — Concrete CMS 9.5.0 and below is vulnerable to IDOR in '/ccm/frontend/conversations/message_page' allowing unauthenticated read of any conversation message
Concrete CMS 9.5.0 and below is vulnerable to IDOR. The '/ccm/frontend/conversations/message_page' endpoint returns the full content of any conversation message. An unauthentica…
Published: 2026-05-21 · CVSS: 6.3 · CVSS 4.0
Concrete CMS 9.5.0 and below is vulnerable to IDOR. The '/ccm/frontend/conversations/message_page' 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 Tristan Madani for reporting.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7