CVE-2026-67328 @better-auth/sso before 1.6.21 Account Takeover via SSO
Attackers can bypass SSO authentication via parsing mismatches or XSS to sign in as arbitrary users and take over accounts.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-67328?
CVE-2026-67328 is a high-severity authentication bypass vulnerability in better-auth sso, published on 1 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
@better-auth/sso versions before 1.6.21 contain multiple authentication bypass vulnerabilities in SSO provider handling that allow attackers to sign in as arbitrary users. Attackers can exploit domain verification parsing mismatches, orphaned provider accounts, unbound SAML assertions, or reflected XSS on logout endpoints to gain unauthorized session access and account takeover.
Weakness: CWE-79
Which versions are affected by CVE-2026-67328?
How do I fix CVE-2026-67328?
No fix has been published for CVE-2026-67328 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-67328 being exploited?
There is no known exploitation of CVE-2026-67328 in the wild and no public exploit code.
Sources
Also known as GHSA-8g2f-78cq-p655, GHSA-prpr-5gj3-qqhg.