High severity · published Jul 15, 2026
CVE-2026-53516
Better Auth: Account takeover via OAuth auto-link to unverified pre-registered email
8.3
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BE
better-auth · better-auth
< 1.6.11 · source: vendor
BA
Better Auth · Better-auth
before 1.6.11 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53516
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-53516
Patch
https://github.com/better-auth/better-auth/commit/da7e50beee849c59a2ed1ec6b3a38cc6ab9fb563
Issue Tracking
https://github.com/better-auth/better-auth/pull/9578
Release Notes
https://github.com/better-auth/better-auth/releases/tag/v1.6.11
Mitigation
https://github.com/better-auth/better-auth/security/advisories/GHSA-g38m-r43w-p2q7
More from better-auth
9.6
CVE-2026-53513
Better Auth: Server-side request forgery via unvalidated OIDC endpoints on @better-auth/sso provider registration
9.3
CVE-2025-61928
Better Auth: Unauthenticated API key creation through api-key plugin
9.1
CVE-2026-114607
better-auth: OAuth state can be used as a Magic Link to sign in as another user
9.1
CVE-2026-110862
Better Auth 1.4.0-beta.18 before 1.7.7 Authentication Bypass via Magic Link
9.1
CVE-2026-53512
Better Auth: OAuth refresh-token replay via missing client authentication on oidc-provider and mcp plugins
