CVE-2026-107369

The auth0/nextjs-auth0 SDK validates that the returnTo parameter is a same-origin URL. The SDK then stores this value and, in a later step, reconstructs it for the post-authentication redirect. The reconstruction logic can produce a URL that browsers interpret as an absolute or scheme-relative path, leading to a redirect to an unintended domain.

• https://github.com/auth0/nextjs-auth0/security/advisories/GHSA-5vvp-h2v6-59j6
• https://trust.okta.com/security-advisories/improper-validation-of-post-login-redirect-url-in-nextjs-auth0-cve-2026-107369