Account takeover via unchecked OAuth auto-linking
Published Jul 15, 2026 · Updated Jul 15, 2026
Improper authentication in Better Auth before 1.6.11 allows remote attackers to take over accounts through OAuth auto-linking. The handleOAuthUserInfo gate trusts the provider's email_verified claim without checking the matched local row's emailVerified flag, so a pre-registered victim address receives the victim's OAuth identity. Exploitation requires email-and-password sign-up, an OAuth or SSO provider, implicit linking, and the victim's later provider sign-in; the attacker retains password access.
Summary
What happened
Improper authentication in Better Auth before 1.6.11 allows remote attackers to take over accounts through OAuth auto-linking. The handleOAuthUserInfo gate trusts the provider's email_verified claim without checking the matched local row's emailVerified flag, so a pre-registered victim address receives the victim's OAuth identity. Exploitation requires email-and-password sign-up, an OAuth or SSO provider, implicit linking, and the victim's later provider sign-in; the attacker retains password access.
The record
- CVE
- CVE-2026-53516
- Published
- Jul 15, 2026
- Updated
- Jul 15, 2026
- Vendor
- Better Auth
- Product
- Better Auth
- Classifications
- CWE-345, CWE-287, T1078
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 15, 2026CVE publishedPublication date reported by the CVE source.
- Jul 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.6.11
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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