ViewComponent/view_component v4.12.0

4.12.0

on GitHub

Fix stale render context on reused component instances. A ViewComponent::Base instance memoized its controller, helpers, request, view context, lookup context, view flow, and requested format details on first render via ||=. Rendering the same instance a second time (intentionally or via aliasing) reused that stale context, which could leak data across requests, sessions, or users. #render_in now resets these ivars on every call so each render derives its context from the current view.

Joel Hawksley

Fix HTML-safety bypass in around_render. ViewComponent::Base#around_render could return HTML-unsafe strings that bypassed the escaping applied to normal #call return values, creating an XSS risk. The vulnerability was amplified in ViewComponent::Collection#render_in, which joined per-item results and unconditionally marked the output html_safe. HTML-unsafe strings returned from around_render are now escaped (with a warning) and Collection#render_in now uses safe_join so unsafe per-item output is escaped instead of laundered into a SafeBuffer.
Joel Hawksley