Simple JWT Login vulnerabilities

The Simple JWT Login plugin in version 4.0.0 contains a Broken Authentication vulnerability. The vulnerability can be exploited by a Subscriber-level user.

The Simple JWT Login WordPress plugin before version 3.6.8 does not validate the audience of Google identity tokens, allowing unauthenticated users to authenticate as any user whose email is in the token, including administrators. All sites with Google sign-in enabled are affected.

The Simple JWT Login plugin for WordPress up to version 3.6.6 contains an authentication bypass and privilege escalation vulnerability. An authenticated attacker with subscriber-level access can inject an administrator's email into the `payload` parameter, resulting in a JWT with admin identity and gaining a fully authenticated admin session.