ShellCodeX vulnerability brief
CRITICAL
Received
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 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.
Published 01 Aug 2026, 13:17 UTC
Last modified 01 Aug 2026, 13:17 UTC
01
Attack profile
The conditions required to exploit this vulnerability and its potential impact.
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Not assessed
Confidentiality
Not assessed
Integrity
Not assessed
Availability
Not assessed
02
Affected products
Product applicability statements supplied with the NVD record.
NVD has not published structured affected-product data for this record.
03
Weakness classification
CWE categories help security teams group the underlying software weakness.
04
Source references
External advisories, patches and technical reports attached to this CVE record.