{"id":"CVE-2026-67335","state":"PUBLISHED","title":"better-auth before 1.6.2 OAuth State Validation Bypass","description":"better-auth versions before 1.6.2 fail to validate the OAuth state parameter against the stored nonce when using cookie-backed state storage without PKCE. Attackers can forge the state parameter and supply an attacker-controlled authorization code to create authenticated sessions bound to the attacker's external identity or persistently link attacker accounts to victim profiles.","publishedAt":"2026-08-01T12:22:17.178Z","updatedAt":"2026-08-03T15:38:08.522Z","severity":{"score":6,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["better-auth better-auth"],"affected":[{"vendor":"better-auth","product":"better-auth","packageURL":"pkg:npm/better-auth","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.6.2","versionType":"semver"},{"version":"1.6.2","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/better-auth/better-auth/security/advisories/GHSA-wxw3-q3m9-c3jr","https://www.vulncheck.com/advisories/better-auth-before-oauth-state-validation-bypass"],"weaknesses":["CWE-287"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/67xxx/CVE-2026-67335.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-67335","state":"PUBLISHED","datePublished":"2026-08-01T12:22:17.178Z","dateUpdated":"2026-08-03T15:38:08.522Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-07-29T13:07:47.016Z"},"containers":{"cna":{"title":"better-auth before 1.6.2 OAuth State Validation Bypass","descriptions":[{"lang":"en","value":"better-auth versions before 1.6.2 fail to validate the OAuth state parameter against the stored nonce when using cookie-backed state storage without PKCE. Attackers can forge the state parameter and supply an attacker-controlled authorization code to create authenticated sessions bound to the attacker's external identity or persistently link attacker accounts to victim profiles."}],"affected":[{"vendor":"better-auth","product":"better-auth","packageURL":"pkg:npm/better-auth","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.6.2","versionType":"semver"},{"version":"1.6.2","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-wxw3-q3m9-c3jr","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-wxw3-q3m9-c3jr)"},{"url":"https://www.vulncheck.com/advisories/better-auth-before-oauth-state-validation-bypass","name":"VulnCheck Advisory: better-auth before 1.6.2 OAuth State Validation Bypass","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","lang":"en","description":"Improper Authentication","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-08-01T12:22:17.178Z"},"datePublic":"2026-05-11T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:better-auth:better-auth\\/oauth-provider:*:*:*:*:*:node.js:*:*","versionEndExcluding":"1.6.2"}]}]}],"credits":[{"lang":"en","value":"Jvr2022","type":"reporter"},{"lang":"en","value":"alavesa","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-03T14:46:54.030129Z","id":"CVE-2026-67335","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":"2026-08-03T15:38:08.522Z"}}]}}}