CVE-2026-67335

MEDIUM

better-auth before 1.6.2 OAuth State Validation Bypass

Title source: cna
STIX 2.1

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's external identity or persistently link attacker accounts to victim profiles.

References (2)

Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-wxw3-q3m9-c3jr)
https://github.com/better-auth/better-auth/security/advisories/GHSA-wxw3-q3m9-c3jr
Third Party Advisory third-party-advisory
VulnCheck Advisory: better-auth before 1.6.2 OAuth State Validation Bypass
https://www.vulncheck.com/advisories/better-auth-before-oauth-state-validation-bypass

Scores

CVSS v3 5.3
EPSS 0.0017
EPSS Percentile 6.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-287
Status published
Products (2)
better-auth/better-auth < 1.6.2
better-auth/better-auth 1.6.2
Published Aug 01, 2026
Tracked Since Aug 01, 2026