jsonwebtoken's insecure implementation of key retrieval function could lead to Forgeable Public/Private Tokens from RSA to HMAC
Overview 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 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. Am I affected? You will be affected if your application is supporting usage of both symmetric key and asymmetric key in jwt.verify() implementation with the same key retrieval function. How do I fix it? Update to version 9.0.0. Will the fix impact my users? There is no impact for end users