CVE-2026-53515

Description

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.

CVSS Vector

References

• https://github.com/better-auth/better-auth/commit/86765f1597378f5c3deed1b80ca91faac0a6bf00
• https://github.com/better-auth/better-auth/pull/9220
• https://github.com/better-auth/better-auth/releases/tag/v1.6.11
• https://github.com/better-auth/better-auth/security/advisories/GHSA-gv74-j8m3-fg5f