MEDIUM
CVE-2026-81921
CVSS
5.4
Description
Concrete CMS 8.5.3 through 9.5.2 enabled the OAuth 2.0 refresh-token grant using the unmodified upstream League grant, which issued new access tokens from a valid refresh token without re-checking the associated account's active status. A user who obtained a refresh token while active could therefore continue to mint valid access tokens after being deactivated or suspended (uIsActive=0), so deactivating an account did not revoke its API access. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L. Thanks sh4d0byss for reporting.
Weakness (CWE)
CWE-862
Missing Authorization
EPSS Score
0.14%
Probability of exploitation in next 30 days
3.5th percentile
Base CVE data derived from NVD (public domain). Enrichment by
dbcve.org
(CC-BY-4.0). Fetched via API.