CVE-2026-67337 better-auth before 1.4.9 Two-Factor Authentication Bypass via session.cookieCache
Attackers with valid credentials can bypass two-factor authentication in better-auth when session caching is enabled, accessing protected routes without second-factor verification.
- 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-2026-67337?
CVE-2026-67337 is a high-severity authentication bypass vulnerability in better-auth, 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 versions before 1.4.9 contain a two-factor authentication bypass vulnerability when session.cookieCache is enabled. Attackers with valid primary credentials can access authenticated routes without completing second-factor verification by exploiting premature session caching.
Weakness: CWE-288
Which versions are affected by CVE-2026-67337?
2 open source packages ship an affected version, including better-auth.
| Package | Affected | Fixed in |
|---|---|---|
better-auth npm | All versions | 1.4.9 |
better-auth npm | All versions | 1.4.9 |
How do I fix CVE-2026-67337?
Upgrade better-auth to 1.4.9 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-67337 being exploited?
There is no known exploitation of CVE-2026-67337 in the wild and no public exploit code.
Sources
Also known as GHSA-8pwm-pjg9-4h92, GHSA-xg6x-h9c9-2m83.