auth0/node-jws is a JSON Web Signature implementation for Node.js. In versions 3.2.2 and earlier and version 4.0.0, auth0/node-jws has an improper signature verification vulnerability when using the HS256 algorithm under specific conditions. Applications are affected when they use the jws.createVerify() function for HMAC algorithms and use user-provided data from the JSON Web Signature protected header or payload in HMAC secret lookup routines, which can allow attackers to bypass signature verification. This issue has been patched in versions 3.2.3 and 4.0.1.