CVE-2026-67336

CVE-2026-67336 affects better-auth versions before 1.6.11, specifically the oidcProvider and mcp plugins. The root cause is insecure cryptographic defaults that advertise the none algorithm and allow plain PKCE by default. This can enable an attacker to exploit algorithm negotiation to accept uns...

CVE-2026-67336 better-auth before 1.6.11 Insecure Cryptographic Defaults via oidcProvider

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...