view_component: System Test Entry Point Path Check Allows Sibling Directory Escape

{
  "id": "d57776d13b55960a118215775e9180fdb5a6fd11fa713755e9a775780c6c3104",
  "url": "https://osv.dev/vulnerability/CVE-2026-44837",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "view_component: System Test Entry Point Path Check Allows Sibling Directory Escape",
    "summary": "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.",
    "evidence": "osv:CVE-2026-44837",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-44837",
      "aliases": [
        "CVE-2026-44837",
        "GHSA-hg3h-g7xc-f7vp"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/viewcomponent/view_component",
              "type": "GIT",
              "events": [
                {
                  "introduced": "c696930250b696fb5528be08edea13a0c78b8325"
                },
                {
                  "fixed": "458281bc49851e3090638cf6d011e84fcd49f2da"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "3.0.0"
                      },
                      {
                        "fixed": "4.9.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:viewcomponent:view_component:*:*:*:*:*:ruby:*:*",
                    "range": [
                      {
                        "introduced": "3.0.0"
                      },
                      {
                        "fixed": "4.9.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v4.8.0",
            "v4.7.0",
            "v4.6.0",
            "v4.5.0",
            "v4.4.0",
            "v4.3.0",
            "v4.2.0",
            "v4.1.1",
            "v3.23.2",
            "v4.1.0",
            "v4.0.2",
            "v4.0.1",
            "v4.0.0",
            "v4.0.0.rc5",
            "v4.0.0.rc4",
            "v4.0.0.rc3",
            "v4.0.0.rc2",
            "v4.0.0.rc1",
            "4.0.0.rc1",
            "v3.23.1",
            "v3.23.0",
            "v3.22.0",
            "v3.21.0",
            "v3.20.0",
            "v3.19.0",
            "v3.18.0",
            "v3.17.0",
            "v3.16.0",
            "v3.15.1",
            "v3.15.0",
            "v3.14.0",
            "v3.13.0",
            "v3.12.1",
            "v3.12.0",
            "v3.11.0",
            "v3.10.0",
            "v3.9.0",
            "v3.8.0",
            "v3.7.0",
            "v3.6.0",
            "v3.5.0",
            "v3.3.0",
            "v3.2.0",
            "v3.1.0",
            "v3.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44837.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.421116150Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44837.json",
        "https://github.com/ViewComponent/view_component/security/advisories/GHSA-hg3h-g7xc-f7vp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-44837"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-187"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44837.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-44837",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504776,
  "published_at": "2026-05-26T19:40:47.661+00:00"
}