### Impact

We found that this vulnerability is present when the developer is implementing an OAuth 1 provider (by extension, it means Twitter, which is the only built-in provider using OAuth 1), but **upgrading** is **still recommended**.

`next-auth` v3 users before version 3.29.3 are impacted. (We recommend upgrading to v4, as v3 is considered unmaintained. See our [migration guide](https://next-auth.js.org/getting-started/upgrade-v4))

`next-auth` v4 users before version 4.3.3 are impacted.

### Patches

We’ve released patches for this vulnerability in:

– v3 – `3.29.3`
– v4 – `4.3.3`

You can do:

“`sh
npm i next-auth@latest
“`

or

“`sh
yarn add next-auth@latest
“`

or

“`sh
pnpm add next-auth@latest
“`

(This will update to the latest v4 version, but you can change `latest` to `3` if you want to stay on v3.)

### Workarounds

If you are not able to upgrade for any reason, you can add the following configuration to your `callbacks` option:

“`ts
// async redirect(url, baseUrl) { // v3
async redirect({ url, baseUrl }) { // v4
// Allows relative callback URLs
if (url.startsWith(“/”)) return `${baseUrl}${url}`
// Allows callback URLs on the same origin
else if (new URL(url).origin === baseUrl) return url
return baseUrl
}
“`

### References

This vulnerability was discovered right after https://github.com/nextauthjs/next-auth/security/advisories/GHSA-f9wg-5f46-cjmw was published and is very similar in nature.

Read more about the `callbacks.redirect` option in the documentation: https://next-auth.js.org/configuration/callbacks#redirect-callback

### For more information

If you have any concerns, we request responsible disclosure, outlined here: https://next-auth.js.org/security#reporting-a-vulnerability

### Timeline

The issue was reported 2022 April 20th, a response was sent out to the reporter 8 minutes after, and a patch was produced within a few days.Read More