CVE-2026-7881: Concrete CMS is subject to Insecure Direct Object Reference (IDOR) in the Express Entry Detail block

May 22, 2026 (updated June 24, 2026)

Concrete CMS 9.5.0 and below is subject to Insecure Direct Object Reference (IDOR) in the Express Entry Detail block via the exEntryID parameter. This IDOR leads to unauthorized access to all Express form submissions. The Concrete CMS security team thanks Tristan Madani for reporting this issue.

References

documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes
github.com/advisories/GHSA-chfm-cm6h-q5x7
nvd.nist.gov/vuln/detail/CVE-2026-7881

Code Behaviors & Features

Detect and mitigate CVE-2026-7881 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →