VULNERABILITY INTELLIGENCE

CVE-2026-67336

CVSS score8.7 HIGH
EPSS probability0.24%
CISA KEVNot currently listed
Published2026-08-01
Last modified2026-09-08
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

Description

better-auth versions before 1.6.11 contain insecure cryptographic defaults in the oidcProvider and mcp plugins that advertise the none algorithm and accept plain PKCE by default. Attackers can exploit algorithm negotiation to accept unsigned tokens or intercept authorization codes when PKCE plain is used instead of the required S256 method.

Weakness classification

  • disclosure@vulncheck.com: CWE-327

Primary references