Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in the Calendar Block since action_get_events does not check canView on the calendar which results in restricted event details being disclosed. 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 lalalala5678 for reporting.
{
"cna_assigner": "ConcreteCMS",
"cwe_ids": [
"CWE-425"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8205.json"
}{
"cpe": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "5.0"
},
{
"last_affected": "9.5.0"
},
{
"introduced": "0"
}
],
"source": [
"AFFECTED_FIELD",
"CPE_RANGE"
]
}