Pow is a authentication and user management solution for Phoenix and Plug-based apps. Starting in version 1.0.14 and prior to version 1.0.34, use of `Pow.Store.Backend.MnesiaCache` is susceptible to session hijacking as expired keys are not being invalidated correctly on startup. A session may expire when all `Pow.Store.Backend.MnesiaCache` instances have been shut down for a period that is longer than a session’s remaining TTL. Version 1.0.34 contains a patch for this issue. As a workaround, expired keys, including all expired sessions, can be manually invalidated.