better-auth Better Auth up to 1.6.10 OAuth Callback Auto-Link Gate /sign-up/email handleOAuthUserInfo email_verified/emailVerified improper authorization

Summaryinfo

A vulnerability categorized as critical has been discovered in better-auth Better Auth up to 1.6.10. This vulnerability affects the function handleOAuthUserInfo of the file /sign-up/email of the component OAuth Callback Auto-Link Gate. The manipulation of the argument email_verified/emailVerified results in improper authorization. This vulnerability was named CVE-2026-53516. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in better-auth Better Auth up to 1.6.10. It has been classified as critical. Affected is the function handleOAuthUserInfo of the file /sign-up/email of the component OAuth Callback Auto-Link Gate. The manipulation of the argument email_verified/emailVerified with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-53516 since 06/09/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

Upgrading to version 1.6.11 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• better-auth

Name

• Better Auth

Version

• 1.6.0
• 1.6.1
• 1.6.2
• 1.6.3
• 1.6.4
• 1.6.5
• 1.6.6
• 1.6.7
• 1.6.8
• 1.6.9
• 1.6.10

CPE 2.3info

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CPE 2.2info

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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