Is CVE-2026-67337 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-67337 being exploited in the wild.

How severe is CVE-2026-67337?

Medium severity, with a CVSS score of 6.5, published 1 August 2026.

Which products and versions are affected?

better-auth (npm) SEMVER:introduced=0,fixed=1.4.9.

Is there a fix for CVE-2026-67337?

Yes. better-auth (npm): upgrade to 1.4.9 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-67337 attacked?

It is attacked over the network.

Am I affected by CVE-2026-67337?

Check whether you run better-auth (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-67337: Better Auth two-factor authentication bypass via premature session caching

CVE-2026-67337 · Severity: medium · CVSS 6.5 · Published 2026-08-01

Better Auth is an authentication framework that supports two-factor authentication (2FA) to protect user accounts. When session caching is enabled, a critical flaw allows attackers to bypass 2FA by using a cached session from before the second authentication factor is verified, gaining full access to protected application routes without completing the second factor.

Technologies: better-auth (npm). Vendors: npm.

Quick answers

Is CVE-2026-67337 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-67337 being exploited in the wild.
How severe is CVE-2026-67337?: Medium severity, with a CVSS score of 6.5, published 1 August 2026.
Which products and versions are affected?: better-auth (npm) SEMVER:introduced=0,fixed=1.4.9.
Is there a fix for CVE-2026-67337?: Yes. better-auth (npm): upgrade to 1.4.9 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-67337 attacked?: It is attacked over the network.
Am I affected by CVE-2026-67337?: Check whether you run better-auth (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

better-auth (npm): upgrade to 1.4.9 or later
```
npm install better-auth@1.4.9
```

Technical details

This is an authentication bypass vulnerability (CWE-288) in Better Auth's session management. When both 2FA and session.cookieCache are enabled, the library caches a session as valid after the initial sign-in but before 2FA verification is complete. Subsequent session lookups return the cached session without re-evaluating the 2FA requirement, allowing an attacker with valid primary credentials to access authenticated routes without completing 2FA. The vulnerability affects version 1.4.5 and earlier; it was fixed in version 1.4.9. The attack requires valid primary credentials and does not require user interaction once primary authentication is obtained. As a temporary mitigation, disabling session.cookieCache when using 2FA can prevent exploitation.

Affected products

Better Auth better-auth < 1.4.9

Identifiers

CVE-2026-67337
GHSA-xg6x-h9c9-2m83

Timeline

2026-04-03: disclosed
2026-04-03: patched: Fix released in version 1.4.9

References

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