{"id":"CVE-2026-110863","title":"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","summary":"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 p…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","cwe":["CWE-287"],"vendor":"better-auth","product":"sso","affected":["sso >= 1.7.0-rc.2 < 1.7.3"],"published":"2026-10-14","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:17:34.130","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-110863","references":[{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-mx9r-x6ww-qjw9","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/better-auth-better-auth-sso-before-1.7.3-authentication-bypass-via-personal-sso-providers","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"epss":0.00269,"epssPercentile":0.18946,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T16:35:48.861225Z"},"ingestedAt":"2026-10-15T00:02:07.186Z","slug":"CVE-2026-110863","body":"## Overview\n\nBetter 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}