view_component: Preview Route Can Dispatch Inherited Helper Methods

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-44836: 0.34% estimated exploitation activity in the next 30 days; percentile 27.93 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The preview route derives an example name from the URL and calls it with publicsend. 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 renderwithtemplate, 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. Severity: High if preview routes are externally reachable; Medium otherwise. Affected files: - lib/viewcomponent/preview.rb - app/controllers/concerns/viewcomponent/previewactions.rb - app/views/viewcomponents/preview.html.erb Relevant Code app/controllers/concerns/viewcomponent/previewactions.rb: lib/viewcomponent/preview.rb: app/views/viewcomponents/preview.html.erb: The UI only lists direct preview methods…

Published by the source

8 May 2026, 23:33 UTC

Last modified by the source

8 Jun 2026, 23:34 UTC

Source last checked

26 Oct 2026, 15:52 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-7f3r-gwc9-2995

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# Patch Next advisory brief: CVE-2026-44836

Advisory: view_component: Preview Route Can Dispatch Inherited Helper Methods
IDs: CVE-2026-44836, GHSA-7f3r-gwc9-2995
Record: https://patchnext.com/advisories/cve-2026-44836 (revision 1, source checked 26 Oct 2026, 15:52 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: view_component 4.9.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems view_component: affected >= 3.0.0, < 4.9.0; fixed in 4.9.0

## Suggested inspection (read-only)
- RubyGems view_component: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on view_component.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-7f3r-gwc9-2995 (GitHub-reviewed advisory GHSA-7f3r-gwc9-2995 lists affected ranges: RubyGems view_component >=3.0.0 <4.9.0)

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