{"id":"CVE-2026-53517","state":"PUBLISHED","title":"Better Auth OAuth Provider: Refresh Token Rotation Race Condition Allows Concurrent Replay and Token Family Forking","description":"Better Auth is an authentication and authorization library for TypeScript. From 1.4.8-beta.7 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint on the refresh_token grant performs a non-atomic read, validate, revoke, and mint sequence on the oauthRefreshToken row, allowing concurrent requests with the same parent refresh token to pass the revoked check and create forked refresh-token families; the vulnerable range also includes embedded better-auth plugin versions before 1.6.0. This issue is fixed in version 1.6.11.","publishedAt":"2026-07-15T17:33:38.943Z","updatedAt":"2026-07-15T19:21:22.553Z","severity":{"score":8.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A: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, < 1.6.0","status":"affected"}]},{"vendor":"@better-auth","product":"oauth-provider","versions":[{"version":">= 1.6.0, < 1.6.11","status":"affected"}]}],"references":["https://github.com/better-auth/better-auth/security/advisories/GHSA-392p-2q2v-4372","https://github.com/better-auth/better-auth/commit/c6918ecc9e3a75892169415d7f6c95b591b6a52d","https://github.com/better-auth/better-auth/releases/tag/v1.6.11"],"weaknesses":["CWE-362","CWE-367"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53517.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53517","state":"PUBLISHED","datePublished":"2026-07-15T17:33:38.943Z","dateUpdated":"2026-07-15T19:21:22.553Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-09T17:30:33.456Z"},"containers":{"cna":{"title":"Better Auth OAuth Provider: Refresh Token Rotation Race Condition Allows Concurrent Replay and Token Family Forking","descriptions":[{"lang":"en","value":"Better Auth is an authentication and authorization library for TypeScript. From 1.4.8-beta.7 until 1.6.11, the @better-auth/oauth-provider POST /oauth2/token endpoint on the refresh_token grant performs a non-atomic read, validate, revoke, and mint sequence on the oauthRefreshToken row, allowing concurrent requests with the same parent refresh token to pass the revoked check and create forked refresh-token families; the vulnerable range also includes embedded better-auth plugin versions before 1.6.0. This issue is fixed in version 1.6.11."}],"affected":[{"vendor":"better-auth","product":"better-auth","versions":[{"version":">= 1.4.8-beta.7, < 1.6.0","status":"affected"}]},{"vendor":"@better-auth","product":"oauth-provider","versions":[{"version":">= 1.6.0, < 1.6.11","status":"affected"}]}],"references":[{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-392p-2q2v-4372","name":"https://github.com/better-auth/better-auth/security/advisories/GHSA-392p-2q2v-4372","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/better-auth/better-auth/commit/c6918ecc9e3a75892169415d7f6c95b591b6a52d","name":"https://github.com/better-auth/better-auth/commit/c6918ecc9e3a75892169415d7f6c95b591b6a52d","tags":["x_refsource_MISC"]},{"url":"https://github.com/better-auth/better-auth/releases/tag/v1.6.11","name":"https://github.com/better-auth/better-auth/releases/tag/v1.6.11","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-362","lang":"en","description":"CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-367","lang":"en","description":"CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-15T17:33:38.943Z"},"source":{"advisory":"GHSA-392p-2q2v-4372","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-15T19:20:42.640935Z","id":"CVE-2026-53517","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-15T19:21:22.553Z"}}]}}}