CVE-2026-85387High· 7.1▾ TwilightConcrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and did not re-check the state of the account the token had been issued to. The resource server's authorization validator confirmed only that a t…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 39.1 · likelihood 0 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 19.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.2%
Last analysed / modified upstream
2 → 7.1
low → high
Concrete CMS before 9.5.4 re-authorized OAuth REST API requests from the bearer token alone and did not re-check the state of the account the token had been issued to. The resource server's authorization validator confirmed only that a token existed, had not expired, and had not been explicitly revoked, and deactivating a user did not revoke that user's outstanding tokens. As a result, a deactivated user retained full access to /ccm/api/1.0/* for the remaining lifetime of any token already issued to them. The same gap applied to accounts that had been deleted or locked pending a forced password reset. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Myq Larson for reporting.
concrete_cms < 9.5.4Upgrade past the affected range:
concrete_cms 9.5.4Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-85385Critical· 9.6Concrete CMS below 9.5.4 did not validate the user timezone value (uTimezone) on write and rendered it without output encoding on the Dashboard user management page, where Date::getTimezoneDisplayName() returns any non-IANA value unchang…
CVE-2026-85386Medium· 6.1Concrete CMS before 9.5.4 did not sanitize XML and XSLT documents uploaded through a public Form Block file-upload question
CVE-2026-87028Medium· 6.5Concrete CMS 9 through 9.5.3 did not confirm that a board InstanceItem submitted to the custom-slot preview endpoint belonged to the board instance the requesting user was authorized to edit, and did not enforce page-view permission befo…
CVE-2026-87031Low· 2.7n Concrete CMS 9.2.0 through 9.5.3, the REST API user creation endpoint (POST /ccm/api/1.0/users, the add() method of concrete/src/Api/Controller/Users.php) did not perform a permission check before creating an account
CVE-2026-81926Medium· 6.1Concrete CMS 9.4.0 through 9.5.2 did not escape colliding page paths before rendering them in the location panel's duplicate-path confirmation dialog
CVE-2026-18426Medium· 6.5Concrete CMS 9.0.0 through 9.5.2 did not enforce a block-level edit-permission check on the Express Form block's control-management actions, which relied solely on CSRF token validation