MajorCritical vulnerability

CVE-2026-110863 (CVSS 8.6)

NVD · officialPublished Oct 14, 2026Risk 37/100EPSS 0.3%

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.

Technical details

CVSS

8.6

AV:NetworkAC:LowPR:LowUI:None

Evidence and sources

This record is attributed to NVD. Exploitation status and remediation guidance are kept separate from the vulnerability's technical severity.

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