CVE-2026-67336
better-auth before 1.6.11 Insecure Cryptographic Defaults via oidcProvider
CVSS Score
8.7
EPSS Score
0.0%
EPSS Percentile
0th
better-auth versions before 1.6.11 contain insecure cryptographic defaults in the oidcProvider and mcp plugins that advertise the none algorithm and accept plain PKCE by default. Attackers can exploit algorithm negotiation to accept unsigned tokens or intercept authorization codes when PKCE plain is used instead of the required S256 method.
| CWE | CWE-327 |
| Vendor | better-auth |
| Product | better-auth |
| Published | Aug 1, 2026 |
Stay Ahead of the Next One
Get instant alerts for better-auth better-auth
Be the first to know when new high vulnerabilities affecting better-auth better-auth are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
better-auth / better-auth
0 < 1.6.11
References
Credits
🔍 subhanUmer