Auth bypass in Better-Auth Oauth-Provider
CVE-2026-67332
@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.
EPSS: 0.002 (5.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.
Affected products
- Better-auth Oauth-provider — versions 1.4.8, 1.7.0-beta.4
Weakness classification (CWE)
References
- disclosure@vulncheck.com (vendor-advisory)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-67332?
- CVE-2026-67332 is a medium-severity vulnerability in Better-Auth Oauth-Provider, classified under Improper Authorization. CVSS score: 6.4/10. Published 2026-08-01.
- How severe is CVE-2026-67332?
- Medium severity. CVSS v3 base score is 6.4 out of 10.