What’s Vulnerable › Vulnerabilities
CVE-2026-18120: Missing Authorization in legacy Express entries search endpoint allows disclosure of Express entry data
- Severity: medium (CVSS 5.9 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-16 · updated 2026-09-21
- Weakness: CWE-862
Description
Concrete CMS before 9.5.3 exposed a legacy Express entry search endpoint that returned entry result JSON without invoking the canViewExpressEntries() permission check applied by the normal dashboard and CSV Export flow. An unauthenticated visitor who knew or discovered an Express entity identifier could enumerate that entity's entry search results, disclosing attribute values intended to be restricted to privileged users. For Express entities that do not support entry-specific permissions (i.e., supportsEntrySpecificPermissions() returns false), per-entry permission filtering is additionally disabled via EntryList::ignorePermissions(). The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Daniel Powell for reporting.
Affected products
- Concrete CMS: before 9.5.4 — fixed in 9.5.4
How to fix
Upgrade to a fixed version: Concrete CMS 9.5.4. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-18120 or the next vulnerability affects your stack