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CVE-2026-53516

Status: AnalyzedHigh (8.3)—

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

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

UI:R indica interacción del usuario (aceptar OAuth). El atacante vincula identidades OAuth a cuentas preregistradas sin verificación de email, logrando acceso no autorizado y tomar control de cuentas existentes.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Multi-factor AuthenticationUser Account ManagementPrivileged Account ManagementPassword PoliciesNetwork SegmentationDisable or Remove Feature or Program

Affected technologies (1)

Better-auth — Better Auth

CWEs

References

Raw JSON (NVD)

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