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 plain PKCE by default. Attackers can exploit algorithm negotiation to accept unsigned tokens or intercept authorization codes when PKCE plain...

CVE-2026-67336: Use of a Broken or Risky Cryptographic Algorithm

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...

CVE-2026-53512: Improper Authentication

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, the legacy oidcProvider and mcp plugins expose OAuth token endpoints whose refreshtoken grant authenticates only possession of the bound refreshToken row and matching clientid, without verifying the...

Insecure Default Initialization of Resource

Overview better-auth is a The most comprehensive authentication library for TypeScript. Affected versions of this package are vulnerable to Insecure Default Initialization of Resource in the oidcProvider. An attacker can gain unauthorized access or impersonate users by exploiting insecure...

PT-2026-60909

Am I affected? Users are affected if all of the following are true: - Their application uses better-auth at a version below the patched release. - Their application enables oidcProvider from better-auth/plugins/oidc-provider or mcp from better-auth/plugins/mcp the mcp plugin delegates to...