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.
Advisories

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Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 03 Aug 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sat, 01 Aug 2026 14:30:00 +0000

Type Values Removed Values Added
First Time appeared Better-auth better Auth
Vendors & Products Better-auth better Auth

Sat, 01 Aug 2026 12:45:00 +0000

Type Values Removed Values Added
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.
Title better-auth before 1.6.2 OAuth State Validation Bypass
First Time appeared Better-auth
Better-auth better-auth\/oauth-provider
Weaknesses CWE-287
CPEs cpe:2.3:a:better-auth:better-auth\/oauth-provider:*:*:*:*:*:node.js:*:*
Vendors & Products Better-auth
Better-auth better-auth\/oauth-provider
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N'}

cvssV4_0

{'score': 6, '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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-03T15:38:08.522Z

Reserved: 2026-07-29T13:07:47.016Z

Link: CVE-2026-67335

cve-icon Vulnrichment

Updated: 2026-08-03T14:46:55.165Z

cve-icon NVD

Status : Received

Published: 2026-08-01T13:17:04.403

Modified: 2026-08-03T17:16:41.833

Link: CVE-2026-67335

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-02T03:15:03Z

Weaknesses