high8.7
CVE-2026-67336
better-auth versions before 1.6.11 contain insecure cryptographic defaults in the oidcProvider and mcp plugins that advertise the none algorithm and accept pla…
Impact
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.
Affected products
| Product | Affected versions |
|---|---|
| Better-Auth | before 1.6.11 |
Versions were read from the advisory text. No structured product data has been published for this record yet.