CRITICAL 9.4 NVD
CVE-2026-67336
better-auth versions before 1.6.11 contain insecure cryptographic defaults in the oidcProvider and mcp plugins that advertise the none algorithm and accept plai
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.
References
- https://github.com/better-auth/better-auth/security/advisories/GHSA-9h47-pqcx-hjr4
- https://www.vulncheck.com/advisories/better-auth-before-insecure-cryptographic-defaults-vi
This critical severity vulnerability with a CVSS score of 9.4 was published on 2026-08-01 via NVD.
Risk Timeline
CVE Disclosed2026-08-01 · 2 days ago
Remediation Resources
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