{"id":"CVE-2026-126436","summary":"OpenEMR before 8.5.0 OAuth2 Grant Type Enforcement Bypass via Token Endpoint","details":"OpenEMR before 8.5.0 contains an authorization bypass vulnerability that allows OAuth2 clients to use unregistered grant types because oauth_clients.grant_types is never enforced. Attackers can request tokens with grant_type=password to bypass the user consent screen, and disabled clients can redeem authorization codes using JWT client assertions.","aliases":["GHSA-qjj7-c4m9-6f92"],"modified":"2026-11-14T10:31:04.047180404Z","published":"2026-11-13T09:35:22.891Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126436.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-862"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/126xxx/CVE-2026-126436.json"},{"type":"ADVISORY","url":"https://github.com/openemr/openemr/security/advisories/GHSA-qjj7-c4m9-6f92"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126436"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/openemr-before-8.5.0-oauth2-grant-type-enforcement-bypass-via-token-endpoint"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openemr/openemr","events":[{"introduced":"0"},{"fixed":"c1b2b8bcbe91aa81858f7ba8b25c31d9a82639a5"}],"database_specific":{"extracted_events":[{"source":"AFFECTED_FIELD","strategy":"StandardRange","range":[{"introduced":"0"},{"fixed":"8.5.0"}]}]}}],"versions":["v3_0_1","v3_0_0","v2_9_0","v2_8_3","v2_8_2","v2_8_1","v2_8_0","v2_7_3-rc1","v2_7_2","v2_7_2-rc2","v2_7_2-rc1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-126436.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"}]}