{"id":"CVE-2026-41427","state":"PUBLISHED","title":"Better Auth OAuth 2.1 Provider: Unprivileged users can register OAuth clients","description":"Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.5, the clientPrivileges option documents a create action, but the OAuth client creation endpoints did not invoke the hook before persisting new clients. Deployments that configured clientPrivileges to restrict client registration were not actually restricted — any authenticated user could reach the create endpoints and register an OAuth client with attacker-chosen redirect URIs and metadata. This vulnerability is fixed in 1.6.5.","publishedAt":"2026-04-24T19:23:20.161Z","updatedAt":"2026-04-27T13:42:23.885Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["better-auth better-auth","better-auth oauth-provider"],"affected":[{"vendor":"better-auth","product":"better-auth","versions":[{"version":">= 1.4.8-beta.7, < 1.6.5","status":"affected"},{"version":">= 1.7.0-beta.0, <= 1.7.0-beta.1","status":"affected"}]},{"vendor":"better-auth","product":"oauth-provider","versions":[{"version":">= 1.4.8-beta.7, < 1.6.5","status":"affected"},{"version":">= 1.7.0-beta.0, <= 1.7.0-beta.1","status":"affected"}]}],"references":["https://github.com/better-auth/better-auth/security/advisories/GHSA-xr8f-h2gw-9xh6"],"weaknesses":["CWE-863"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/41xxx/CVE-2026-41427.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-41427","state":"PUBLISHED","datePublished":"2026-04-24T19:23:20.161Z","dateUpdated":"2026-04-27T13:42:23.885Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-20T15:32:33.814Z"},"containers":{"cna":{"title":"Better Auth OAuth 2.1 Provider: Unprivileged users can register OAuth clients","descriptions":[{"lang":"en","value":"Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.5, the clientPrivileges option documents a create action, but the OAuth client creation endpoints did not invoke the hook before persisting new clients. Deployments that configured clientPrivileges to restrict client registration were not actually restricted — any authenticated user could reach the create endpoints and register an OAuth client with attacker-chosen redirect URIs and metadata. This vulnerability is fixed in 1.6.5."}],"affected":[{"vendor":"better-auth","product":"better-auth","versions":[{"version":">= 1.4.8-beta.7, < 1.6.5","status":"affected"},{"version":">= 1.7.0-beta.0, <= 1.7.0-beta.1","status":"affected"}]},{"vendor":"better-auth","product":"oauth-provider","versions":[{"version":">= 1.4.8-beta.7, < 1.6.5","status":"affected"},{"version":">= 1.7.0-beta.0, <= 1.7.0-beta.1","status":"affected"}]}],"references":[{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-xr8f-h2gw-9xh6","name":"https://github.com/better-auth/better-auth/security/advisories/GHSA-xr8f-h2gw-9xh6","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-863","lang":"en","description":"CWE-863: Incorrect Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-24T19:23:20.161Z"},"source":{"advisory":"GHSA-xr8f-h2gw-9xh6","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-27T13:42:15.023332Z","id":"CVE-2026-41427","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-27T13:42:23.885Z"}}]}}}