NextAuth.js (next-auth) is am open source authentication solution for Next.js applications. Prior to versions 3.29.3 and 4.3.3, an open redirect vulnerability is present when the developer is implementing an OAuth 1 provider. Versions 3.29.3 and 4.3.3 contain a patch for this issue. The maintainers recommend adding a certain configuration to one's `callbacks` option as a workaround for those unable to upgrade.

Affected: npm: next-auth

### 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.r…