CVE-2026-67332: Better-Auth OAuth-Provider

Medium severity, CVSS 6.4. EPSS: 0.3% chance of exploitation in the next 30 days.

@better-auth/oauth-provider before 1.7.0-beta.4 fails to bind access-token audience to the authorization grant, allowing clients to request tokens for unrelated resources. Attackers can complete an OAuth flow and obtain access tokens whose audience targets resource servers the authorization never covered, bypassing intended authorization boundaries.

Affected products

• Better-Auth OAuth-Provider: from 1.4.8, before 1.7.0-beta.4 (fixed in 1.7.0-beta.4)

Published 2026-08-01. Last modified 2026-10-08.