CVE-2026-8240: Concrete CMS 9.5.0 and below is vulnerable to unauthenticated page metadata disclosure in Backend\SummaryTemplate

Published May 21, 2026
·
Updated

Concrete CMS 9.5.0 and below is vulnerable to unauthenticated page metadata disclosure across every page with a configured summary template, revealing the existence of private, draft, and restricted pages while leaking title, path, description, and author information. 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 Winston Crooker for reporting.

Affected Software

2 affected components
Concrete CMS Concrete CMS<=9.5.0
ConcreteCMS Concrete CMS<9.5.1

Event History

May 21, 2026
CVE Published
via MITRE·09:11 PM
Data Sourced
via MITRE·09:11 PM
DescriptionWeakness
Data Sourced
via NVD·10:16 PM
DescriptionSeverityWeaknessAffected Software
Jun 23, 58372
Event
via FIRST·04:31 AM

Frequently Asked Questions

1

What is the severity of CVE-2026-8240?

The severity of CVE-2026-8240 is classified as medium with a CVSS score of 6.3.

2

How do I fix CVE-2026-8240?

To fix CVE-2026-8240, update Concrete CMS to version 9.5.1 or later.

3

What information can be disclosed due to CVE-2026-8240?

CVE-2026-8240 allows unauthenticated users to access page metadata, revealing details about private, draft, and restricted pages.

4

Which versions of Concrete CMS are affected by CVE-2026-8240?

Concrete CMS versions 9.5.0 and below are vulnerable to CVE-2026-8240.

5

What type of vulnerability is CVE-2026-8240?

CVE-2026-8240 is a vulnerability related to unauthenticated page metadata disclosure.

Contact

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