CVE-2026-18122 Concrete CMS 9.2.0 to 9.5.2 Express REST API list endpoint exposes restricted Express entries via Missing Authorization
Attackers with read scope can enumerate restricted Express entries and view sensitive data via the REST API list endpoint.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-18122?
CVE-2026-18122 is a medium-severity missing authorization vulnerability in Concrete CMS, published on 11 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Concrete CMS 9.2.0 to 9.5.2 Express REST API list endpoint exposes restricted Express entries via Missing Authorization; the Concrete CMS REST API's Express entry collection endpoint disabled the per-entry view permission check. An OAuth token with read scope for an Express entity could enumerate entries that its user context lacked permission to view, disclosing each entry's public identifier, URL, label, dates, and any attribute or associated-entry data requested via the includes parameter. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 6.0 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.
Weakness: CWE-862
Which versions are affected by CVE-2026-18122?
How do I fix CVE-2026-18122?
No fix has been published for CVE-2026-18122 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-18122 being exploited?
There is no known exploitation of CVE-2026-18122 in the wild and no public exploit code.
Sources
Also known as GHSA-323h-prp6-6hg9.