CVE-2026-8205CWE-425

Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in Calendar Block since action_get_events does not check canView on the calendar

Medium · published May 21, 2026

CVSS v4.0
6.3
EPSS
0%
Percentile
27.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
6.3 · MEDIUM
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
EPSS
0.00353 · 27.8th percentile
Weakness
CWE-425 · Direct Request ('Forced Browsing')
Published
2026-05-21T20:57Z
EPSS history
Timeline
  • 21 MAY 20:57Z
    Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in Calendar Block since action_get_events does not check canView on the calendar
    cvelistv5