CVE-2026-67335

better-auth versions before 1.6.2 fail to validate the OAuth state parameter against the stored nonce when using cookie-backed state storage without PKCE. Attackers can forge the state parameter and supply an attacker-controlled authorization code to create authenticated sessions bound to the attacker's external identity or persistently link attacker accounts to victim profiles.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/better-auth/better-auth/security/advisories/GHSA-wxw3-q3m9-c3jr
https://www.vulncheck.com/advisories/better-auth-before-oauth-state-validation-bypass

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-01 13:17

Updated : 2026-09-08 20:34

NVD link : CVE-2026-67335

Mitre link : CVE-2026-67335

CVE.ORG link : CVE-2026-67335

JSON object : View

Products Affected

No product.

CWE

CWE-287

Improper Authentication

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