What’s Vulnerable › Vulnerabilities

CVE-2026-53516: Better Auth: Account takeover via OAuth auto-link to unverified pre-registered email

• Severity: high (CVSS 8.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-15 · updated 2026-07-21
• Weakness: CWE-287

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.

Affected products

• better-auth: before 1.6.11 — fixed in 1.6.11

How to fix

Upgrade to a fixed version: better-auth 1.6.11. Check the vendor advisory for mitigations.

References

• https://github.com/better-auth/better-auth/commit/da7e50beee849c59a2ed1ec6b3a38cc6ab9fb563
• https://github.com/better-auth/better-auth/pull/9578
• https://github.com/better-auth/better-auth/releases/tag/v1.6.11
• https://github.com/better-auth/better-auth/security/advisories/GHSA-g38m-r43w-p2q7

Get alerted when CVE-2026-53516 or the next vulnerability affects your stack