Techniques for providing network slice-based security in mobile networks (e.g., service provider networks for mobile subscribers) are disclosed. In some embodiments, a system/process/computer program product for network slice-based security in mobile networks in accordance with some embodiments includes monitoring network traffic on a service provider network at a security platform to identify a new session, wherein the service provider network includes a 5G network or a converged 5G network; extracting network slice information for user traffic associated with the new session at the security platform; and determining a security policy to apply at the security platform to the new session based on the network slice information.