high8.4
CVE-2026-41427
Better Auth is an authentication and authorization library for TypeScript.
Impact
Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.5, the clientPrivileges option documents a create action, but the OAuth client creation endpoints did not invoke the hook before persisting new clients. Deployments that configured clientPrivileges to restrict client registration were not actually restricted — any authenticated user could reach the create endpoints and register an OAuth client with attacker-chosen redirect URIs and metadata. This vulnerability is fixed in 1.6.5.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @better-auth/oauth-provider | >= 1.4.8-beta.7, < 1.6.5 | 1.6.5 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Better-Auth | Better-Auth\/Oauth-Provider | from 1.4.9 before 1.6.5 Versions 1.4.8, 1.7.0 |