CVE-2026-41427
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.
- CVSS 4.0
- 7.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N - CVSS 3.1
- 6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N - EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 11% of CVEs (scores of 2026-10-26)
- CWE
- CWE-863
- Published
- Modified
- Record from
- the NVD, synced
Affected
- better-auth:better-auth\/oauth-provider
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-xr8f-h2gw-9xh6 | npm | @better-auth/oauth-provider | >=1.4.8-beta.7 <1.6.5 | 1.6.5 |
| GHSA-xr8f-h2gw-9xh6 | npm | @better-auth/oauth-provider | >=1.7.0-beta.0 <=1.7.0-beta.1 | no fix published |