View Component

view_component is a framework for building reusable, testable, and encapsulated view components in Ruby on Rails. From 4.0.0 until 4.12.0, ViewComponent::Base#around_render can return HTML-unsafe strings that bypass the escaping behavior applied to normal #call return values. This creates an XSS risk when downstream applications use around_render to wrap, replace, instrument, or conditionally return content that includes user-controlled data, and ViewComponent::Collection#render_in can amplify the issue by joining per-item results and marking the entire output html_safe, converting raw unsafe output into an ActiveSupport::SafeBuffer. This issue is fixed in version 4.12.0.

Published: 2026-07-17T20:46:52.176Z
Updated: 2026-07-20T17:38:56.324Z

view_component is a framework for building reusable, testable, and encapsulated view components in Ruby on Rails. From 4.0.0 until 4.12.0, ViewComponent::Base instances retain render-scoped objects across calls to render_in; if the same component, collection, or spacer component instance is reused across requests, users, tenants, or threads, later renders can use stale helpers, controller, request, view_flow, format/variant details, and slot child context from an earlier render. This can cause authorization-aware components to render privileged UI for a lower-privileged user, generate links using a stale Host header, leak slot/helper state, and mix request context under concurrent rendering. This issue is fixed in version 4.12.0.

Published: 2026-07-17T20:45:28.338Z
Updated: 2026-07-20T13:46:20.930Z

view_component is a framework for building reusable, testable, and encapsulated view components in Ruby on Rails. From 3.0.0 to 4.9.0, the system test entrypoint canonicalizes a user-controlled file path with File.realpath, then checks whether the resolved path starts with the temp directory path. This is not a safe containment check because sibling directories can share the same string prefix. This vulnerability is fixed in 4.9.0.

Published: 2026-05-26T19:40:47.661Z
Updated: 2026-05-28T14:04:27.716Z

view_component is a framework for building reusable, testable, and encapsulated view components in Ruby on Rails. From 3.0.0 to 4.9.0, the preview route derives an example name from the URL and calls it with public_send. The code does not verify that the requested method is one of the preview examples explicitly defined by the preview class. As a result, inherited public methods on ViewComponent::Preview are route-reachable. The most important one is render_with_template, which accepts template: and locals:. Those values can come from request params and are later passed to Rails as render template:. If previews are exposed, an attacker can render internal Rails templates that are not otherwise routable. This vulnerability is fixed in 4.9.0.

Published: 2026-05-26T19:43:58.008Z
Updated: 2026-05-27T13:21:54.259Z

view_component is a framework for building reusable, testable, and encapsulated view components in Ruby on Rails. Versions prior to 3.9.0 and 2.83.0 have a cross-site scripting vulnerability that has the potential to impact anyone rendering a component directly from a controller with the view_component gem. Note that only components that define a `#call` method (i.e. instead of using a sidecar template) are affected. The return value of the `#call` method is not sanitized and can include user-defined content. In addition, the return value of the `#output_postamble` methodis not sanitized, which can also lead to cross-site scripting issues. Versions 3.9.0 and 2.83.0 have been released and fully mitigate both the `#call` and the `#output_postamble` vulnerabilities. As a workaround, sanitize the return value of `#call`.

Published: 2024-01-04T20:09:08.564Z
Updated: 2025-06-17T20:29:11.989Z