Description
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.
Affected products
viewcomponent: view component
References4
- github.com/ViewComponent/view_component/security/advisories/GHS… ExploitMitigationVendor Advisory
- github.com/ViewComponent/view_component/security/advisories/GHS… ExploitMitigationVendor Advisory
- github.com/ViewComponent/view_component/commit/6796b2e89d0bd7b9… Patch
- github.com/ViewComponent/view_component/releases/tag/v4.12.0 ProductRelease Notes
Metrics
- CVSS 3.1
-
6.8
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N - EPSS — exploit probability
- 0% percentile: 27 · as of 14 November 2026
- CWE
- CWE-362CWE-488CWE-668
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.