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 i…

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• cpe concretecms/concrete cmsversion unspecified

How to fix CVE-2026-8205

• No stored fix

  No vendor fix text is stored. Use the linked advisory before you change production.

• Version check

  No version range is stored, so an installed version cannot be checked on this page.

• Advisory

  Open the cve_org record and follow its fix.

• Official advisories

  • CVE.org · cve.org
  • FIRST EPSS · first.org
  • NIST NVD · nvd.nist.gov

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

1. May 21, 2026 · NIST NVD

   Detected

   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 reporti

2. Jul 23, 2026 · NIST NVD

   Updated

   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 reporti

Sources

• CVE.orgVulnerability recordCVE-2026-8205

  Official CVE identifier

  cve.org
• FIRST EPSSExploitation probabilityCVE-2026-8205

  30-day exploitation probability 0.21%

  first.org
• NIST NVDVulnerability recordCVE-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. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 s

  nvd.nist.gov

References

• Release Notes · documentation.concretecms.org

Freshness

Last verified in this catalog Oct 25, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

• FIRST EPSSOct 25, 2026
• NIST NVDOct 18, 2026
• CVE.orgOct 16, 2026