CVE-2026-67336 (GCVE-0-2026-67336)
Vulnerability from cvelistv5 – Published: 2026-08-01 12:22 – Updated: 2026-08-03 15:23
VLAI
EPSS
VEX
Title
better-auth before 1.6.11 Insecure Cryptographic Defaults via oidcProvider
Summary
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.
Severity
8.7 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-03 15:23 UTC
CWE
- CWE-327 - Use of a Broken or Risky Cryptographic Algorithm
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/better-auth/better-auth/securi… | vendor-advisory |
| https://www.vulncheck.com/advisories/better-auth-… | third-party-advisory |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| better-auth | better-auth |
Affected:
0 , < 1.6.11
(semver)
Unaffected: 1.6.11 (semver) cpe:2.3:a:better-auth:better-auth\/oauth-provider:*:*:*:*:*:node.js:*:* |
Date Public
2026-05-31 00:00
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