CVE-2026-67335

Medium

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.

SeverityMedium

CVSS5.3

Exploit probability—

ProductBetter-auth

PublishedAug 1, 2026

First seenAug 1, 2026

Weakness typeCWE-287Improper authentication

How to fix

Update

better-auth1.6.2 or later

Vendor advisories

github.com/better-auth/better-auth/security/advisories/GHSA-wxw3-q3m9-c3jr

Affected products

Product	Affected versions	Fixed in
better-authnpm	v < 1.6.2	1.6.2

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.