CVE-2026-44837 is a medium-severity path traversal vulnerability in view_component (rubygems), affecting versions >= 3.0.0, < 4.9.0. It is fixed in 4.9.0.
Summary 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. Severity: Medium; test-route scoped. Example: The outside path is not inside the base directory, but it passes: Relevant Code app/controllers/viewcomponentssystemtestcontroller.rb: The route then renders the resolved file: Exploit Flow Example request: Flow: basepath resolves to .../tmp/viewcomponents. The payload resolves to .../tmp/viewcomponentsevil/secret.html.erb. That path is outside the intended temp directory. The string prefix check still passes. Rails renders the sibling file. The route is mounted only in Rails.env.test?, which is why Medium is more appropriate than P1. The issue matters if test routes are reachable in shared CI, staging, review apps, or any accidentally exposed test-mode deployment. Targeted Fuzz Result The following sibling paths passed an equivalent realpath plus startwith? harness while resolving outside the base directory: PoC Test Create test/sandbox/test/systemtestentrypointpathtraversalpoctest.rb: Run: Vulnerable behavior: the response succeeds and contains VCSYSTEMTESTTRAVERSALPOC. Fixed behavior: the request raises ViewComponent::SystemTestControllerNefariousPathError or otherwise fails without rendering the file. Suggested Fix Use path-aware containment instead of a raw string prefix. For example: Or require a separator boundary: Add regression tests for: A normal temp file inside tmp/viewcomponents ../../README.md ../viewcomponentsevil/secret.html.erb A symlink inside the temp directory that resolves outside it
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2026-44837 has a CVSS score of 5.9 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (4.9.0). Upgrading removes the vulnerable code path.
rubygems
view_component (>= 3.0.0, < 4.9.0)view_component → 4.9.0 (rubygems)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
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Upgrade view_component to 4.9.0 or later to resolve this vulnerability.
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-44837 is a medium-severity path traversal vulnerability in view_component (rubygems), affecting versions >= 3.0.0, < 4.9.0. It is fixed in 4.9.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
CVE-2026-44837 has a CVSS score of 5.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
view_component (rubygems) versions >= 3.0.0, < 4.9.0 is affected.
Yes. CVE-2026-44837 is fixed in 4.9.0. Upgrade to this version or later.
Whether CVE-2026-44837 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
Upgrade view_component to 4.9.0 or later.