What is CVE-2026-67333?

CVE-2026-67333 is a high-severity vulnerability in Better-auth, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-08-01.

How severe is CVE-2026-67333?

High severity. CVSS v3 base score is 7.2 out of 10.

XSS in Better-auth

CVE-2026-67333

better-auth before 1.6.13 (and pre-release builds 1.7.0-beta.0 through 1.7.0-beta.3) fail to validate the scheme of redirect_uris registered via the deprecated oidc-provider plugin and the mcp plugin (which wraps the same provider). An att…

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Better-auth — versions 0, 1.6.13, 1.7.0-beta.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-67333?: CVE-2026-67333 is a high-severity vulnerability in Better-auth, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-08-01.
How severe is CVE-2026-67333?: High severity. CVSS v3 base score is 7.2 out of 10.