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.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8237.json",
"cna_assigner": "ConcreteCMS",
"cwe_ids": [
"CWE-862"
]
}{
"source": [
"AFFECTED_FIELD",
"CPE_RANGE"
],
"cpe": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "5.0"
},
{
"last_affected": "9.5.0"
},
{
"introduced": "0"
},
{
"fixed": "9.5.1"
}
]
}