SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-8205

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.

MEDIUM 6.3EPSS 0.21%

Does this matter?

Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 4.0
6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.21% probability · 12th percentile
CISA KEV
Not listed
Weakness
CWE-425
Affected
concretecms/concrete cms
Source
ff5b8ace-8b95-4078-9743-eac1ca5451de

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.