JWTs (JSON Web Tokens) are everywhere – frontends, backends, microservices – and for good reason: they're easy to pass around, self-contained, and standardized. But while JWTs can be a solid fit for authentication, using them for authorization is a decision that comes with serious pitfalls – especially in distributed systems.
In this talk, we’ll explore the technical and security limitations of JWT-based authorization and explain why they're fundamentally incompatible with the needs of modern applications. From the infamous ""New Enemy Problem"" described in Google’s Zanzibar paper to the vague semantics of scope claims and the difficulty of revoking tokens in-flight, we’ll unpack the real-world consequences of treating JWTs as your AuthZ layer.
This talk has been presented at JSNation 2026, check out the latest edition of this JavaScript Conference.























