CVE-2026-53515 — Better Auth: Privilege escalation via SSO provider registration: missing admin role check in @better-auth/sso
Better Auth is an authentication and authorization library for TypeScript. From 1.2.10 until 1.6.11, the @better-auth/sso plugin's POST /sso/register endpoint lets any organizat…
Published: 2026-07-15 · CVSS: 7.1 · CVSS 3.1
Better Auth is an authentication and authorization library for TypeScript. From 1.2.10 until 1.6.11, the @better-auth/sso plugin's POST /sso/register endpoint lets any organization member attach a new SSO provider to that organization because registerSSOProvider checks only for a membership row and does not require an owner or admin role, allowing attacker-controlled OIDC or SAML providers to drive /sso/callback/{providerId} organization provisioning. This issue is fixed in version 1.6.11.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7