Vulnerability · Published May 21, 2026 · Assigned by ConcreteCMS
CVE-2026-7881Concrete CMS 9.5.0 and below is vulnerable to IDOR in the Express Entry Detail block
Medium 6.3
In plain English
A medium-severity authorization bypass via user-controlled key in Concrete CMS from Concrete CMS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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 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 Tristan Madani for reporting.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | concrete5/concrete5 | 9.5.1 | GHSA-chfm-cm6h-q5x7 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Concrete CMS | Concrete CMS | 5.0 – before 9.5.0 |
Weakness: CWE-639 · 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