High 8.7Published Aug 1, 2026

CVE-2026-67336better-auth before 1.6.11 Insecure Cryptographic Defaults via oidcProvider

Updated under an hour ago (Oct 26, 2026, 8:50 PM ET)

Does this affect you?

It affects better-auth. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for better-auth

Exploited in the last 30 days

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.

CVSS: 8.7 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
Weakness (CWE): CWE-327
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Aug 3, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

better-auth better-auth better_auth:better_auth (from the name)	before 1.6.11; 1.6.11 not affected	CNA record

References

References

https://github.com/better-auth/better-auth/security/advisories/GHSA-9h47-pqcx-hjr4	vendor-advisory
https://www.vulncheck.com/advisories/better-auth-before-insecure-cryptographic-defaults-via-oidcprovider	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.