Vulnerability Description
Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, Better Auth's OAuth callback auto-link gate in handleOAuthUserInfo accepts implicit account linking when the OAuth provider asserts email_verified: true without requiring the local user row's emailVerified field to also be true, allowing an attacker who pre-registers a victim email through /sign-up/email to bind the victim's OAuth identity to the attacker's account. The same primitive affects one-tap, and emailAndPassword.requireEmailVerification: true does not mitigate the link-time verification change. This issue is fixed in version 1.6.11.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Better-Auth | Better Auth | < 1.6.11 |
Related Weaknesses (CWE)
References
- https://github.com/better-auth/better-auth/commit/da7e50beee849c59a2ed1ec6b3a38cPatch
- https://github.com/better-auth/better-auth/pull/9578Issue TrackingPatch
- https://github.com/better-auth/better-auth/releases/tag/v1.6.11Release Notes
- https://github.com/better-auth/better-auth/security/advisories/GHSA-g38m-r43w-p2MitigationVendor Advisory
FAQ
What is CVE-2026-53516?
CVE-2026-53516 is a vulnerability with a CVSS score of 8.3 (HIGH). Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, Better Auth's OAuth callback auto-link gate in handleOAuthUserInfo accepts implicit account linking when the...
How severe is CVE-2026-53516?
CVE-2026-53516 has been rated HIGH with a CVSS base score of 8.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-53516?
Check the references section above for vendor advisories and patch information. Affected products include: Better-Auth Better Auth.