{"id":"CVE-2026-110863","published":"2026-10-14T23:17:27.830","lastModified":"2026-10-16T18:17:34.130","description":"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.","cvssScore":8.1,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","cwes":["CWE-287"],"vendors":[],"products":[],"references":[{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-mx9r-x6ww-qjw9","tags":[]},{"url":"https://www.vulncheck.com/advisories/better-auth-better-auth-sso-before-1.7.3-authentication-bypass-via-personal-sso-providers","tags":[]}],"exploitRefs":[{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-mx9r-x6ww-qjw9","tags":[]}],"hasPoc":true,"ai":null}