jsonwebtoken is an implementation of JSON Web Tokens. Versions `<= 8.5.1` of `jsonwebtoken` library can be misconfigured so that passing a poorly implemented key retrieval function referring to the `secretOrPublicKey` argument from the readme link will result in incorrect verification of tokens. There is a possibility of using a different algorithm and key combination in verification, other than the one that was used to sign the tokens. Specifically, tokens signed with an asymmetric public key could be verified with a symmetric HS256 algorithm. This can lead to successful validation of forged tokens. If your application is supporting usage of both symmetric key and asymmetric key in jwt.verify() implementation with the same key retrieval function. This issue has been patched, please update to version 9.0.0.

omniauth-auth0 (rubygems) versions >= 2.3.0 and < 2.4.1 improperly validate the JWT token signature when using the `jwt_validator.verify` method. Improper validation of the JWT token signature can allow an attacker to bypass authentication and authorization. You are affected by this vulnerability if all of the following conditions apply: 1. You are using `omniauth-auth0`. 2. You are using `JWTValidator.verify` method directly OR you are not authenticating using the SDK’s default Authorization Code Flow. The issue is patched in version 2.4.1.

Auth0 Passport-SharePoint before 0.4.0 does not validate the JWT signature of an Access Token before processing. This allows attackers to forge tokens and bypass authentication and authorization mechanisms.

Auth0 Auth0-WCF-Service-JWT before 1.0.4 leaks the expected JWT signature in an error message when it cannot successfully validate the JWT signature. If this error message is presented to an attacker, they can forge an arbitrary JWT token that will be accepted by the vulnerable application.

Auth0 angular-jwt before 0.1.10 treats whiteListedDomains entries as regular expressions, which allows remote attackers with knowledge of the jwtInterceptorProvider.whiteListedDomains setting to bypass the domain whitelist filter via a crafted domain.

The Auth0 authentication service before 2017-10-15 allows privilege escalation because the JWT audience is not validated.