CVE-2026-41427

HIGH

Better Auth OAuth 2.1 Provider: Unprivileged users can register OAuth clients

Title source: cna

Description

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.

References (1)

[X_Refsource_Confirm] https://github.com/better-auth/better-auth/security/advisories/GHSA-xr8f-h2gw-9xh6

Scores

CVSS v4 7.1

EPSS 0.0005

EPSS Percentile 15.3%

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-863

Status published

Products (4)

better-auth/better-auth >= 1.4.8-beta.7, < 1.6.5

better-auth/better-auth >= 1.7.0-beta.0, <= 1.7.0-beta.1

better-auth/oauth-provider >= 1.4.8-beta.7, < 1.6.5

better-auth/oauth-provider >= 1.7.0-beta.0, <= 1.7.0-beta.1

Published Apr 24, 2026

Tracked Since Apr 24, 2026