{"id":"CVE-2026-67335","title":"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","summary":"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 authoriz…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N","cwe":["CWE-287"],"published":"2026-08-01","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:34:34.997","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-67335","references":[{"url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-wxw3-q3m9-c3jr","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/better-auth-before-oauth-state-validation-bypass","label":"disclosure@vulncheck.com"}],"tags":["nvd"],"epss":0.00172,"epssPercentile":0.06926,"ingestedAt":"2026-08-02T08:18:07.705Z","slug":"CVE-2026-67335","body":"## Overview\n\nbetter-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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}