CVE-2026-67335

Severity CVSS v4.0:

MEDIUM

Type:

CWE-287 Authentication Issues

Publication date:

01/08/2026

Last modified:

03/08/2026

Description

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&#39;s external identity or persistently link attacker accounts to victim profiles.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 6.00 MEDIUM
Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): High
Attack Requirements (AT): Present
Privileges Required (PR): None
User Interaction (UI): Passsive
Confidentiality (VC): None
Integrity (VI): High
Availability (VA): None
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

6.00

Severity 4.0

MEDIUM

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N CVSS v3.1 Severity and Metrics:

Base Score: 5.30 MEDIUM
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): Required
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): High
Availability (A): None

Base Score 3.x

5.30

Severity 3.x

MEDIUM

CVE-2026-67335

Description

Impact

References to Advisories, Solutions, and Tools