CVE-2021-43812: Open redirect in nextjs-auth0

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-12-16 · updated 2026-06-17
Weakness: CWE-601

Description

The Auth0 Next.js SDK is a library for implementing user authentication in Next.js applications. Versions before 1.6.2 do not filter out certain returnTo parameter values from the login url, which expose the application to an open redirect vulnerability. Users are advised to upgrade as soon as possible. There are no known workarounds for this issue.

Affected products

auth0 nextjs-auth0: before 1.6.2 — fixed in 1.6.2

How to fix

Upgrade to a fixed version: auth0 nextjs-auth0 1.6.2. Check the vendor advisory for mitigations.

References

https://github.com/auth0/nextjs-auth0/commit/0bbd9f8a0c93af51f607f28633b5fb18c5e48ad6
https://github.com/auth0/nextjs-auth0/security/advisories/GHSA-2mqv-4j3r-vjvp
https://github.com/auth0/nextjs-auth0/commit/0bbd9f8a0c93af51f607f28633b5fb18c5e48ad6
https://github.com/auth0/nextjs-auth0/security/advisories/GHSA-2mqv-4j3r-vjvp

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