{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-110863","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-10-14T22:18:33.239Z","datePublished":"2026-10-14T22:52:50.378Z","dateUpdated":"2026-10-16T17:14:33.345Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-10-14T22:52:50.378Z"},"datePublic":"2026-09-29T00:00:00.000Z","title":"Better Auth @better-auth/sso before 1.7.3 Authentication Bypass via Personal SSO Providers","descriptions":[{"lang":"en","value":"Better Auth @better-auth/sso from 1.7.0-rc.2 before 1.7.3 contains an authentication bypass vulnerability that allows authenticated users to sign in as other users by registering a personal SSO provider. Attackers can copy a legitimate provider's OIDC issuer or SAML entity ID and assert a victim's subject or NameID, because account lookup ignores providerId, creating sessions for victim accounts."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improper Authentication","cweId":"CWE-287","type":"CWE"}]}],"affected":[{"vendor":"better-auth","product":"sso","defaultStatus":"unaffected","packageURL":"pkg:npm/%40better-auth/sso","versions":[{"version":"1.7.0-rc.2","status":"affected","versionType":"semver","lessThan":"1.7.3"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:better-auth:better-auth\\/sso:*:*:*:*:*:*:*:*","versionStartIncluding":"1.7.0-rc.2","versionEndExcluding":"1.7.3"}]}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.6,"baseSeverity":"HIGH"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":8.1,"baseSeverity":"HIGH"}}],"references":[{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-mx9r-x6ww-qjw9","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-mx9r-x6ww-qjw9)"},{"name":"VulnCheck Advisory: Better Auth @better-auth/sso before 1.7.3 Authentication Bypass via Personal SSO Providers","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/better-auth-better-auth-sso-before-1.7.3-authentication-bypass-via-personal-sso-providers"}],"credits":[{"lang":"en","value":"manus-use","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-16T16:35:48.861225Z","id":"CVE-2026-110863","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-16T17:14:33.345Z"}}]}}