{"id":23458,"date":"2026-09-16T04:31:36","date_gmt":"2026-09-15T20:31:36","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-81921"},"modified":"2026-09-16T04:31:36","modified_gmt":"2026-09-15T20:31:36","slug":"cve-2026-81921","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-81921","title":{"rendered":"CVE-2026-81921 &#8211; Concrete CMS 8.5.3 through 9.5.2 enabled the OAuth 2.0 refresh-token grant using the unmod"},"content":{"rendered":"<p>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&#8217;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.\u00a0The 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.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>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<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-23458","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/23458","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=23458"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=23458"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=23458"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}