Vitest: Windows backslash traversal bypasses the @vitest/mocker redirect allowlist fix

{
  "id": "c67733ec16018b0dae67c9097afc3157c12f79d02ed36fde005b73cf1950ca8b",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-112950",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vitest: Windows backslash traversal bypasses the @vitest/mocker redirect allowlist fix",
    "summary": "Vitest is a Vite-native testing framework for JavaScript and TypeScript projects. From 4.1.11 until 4.1.12 and 5.0.3, isFileLoadingAllowed and the filesystem read interpret backslashes differently on Windows in packages/mocker/src/node/interceptorPlugin.ts. When a client can reach the Vite dev server on Windows and register a redirect mock containing backslash traversal, POSIX joining preserves a Windows backslash traversal that the later filesystem read interprets as a path separator, so the client can read a file outside server.fs.allow that the Vitest process can access. This issue is fixed in versions 4.1.12 and 5.0.3.",
    "evidence": "cve:CVE-2026-112950",
    "products": [
      {
        "name": {
          "value": "vitest",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      },
      {
        "name": {
          "value": "mocker",
          "evidence": "/containers/cna/affected/1/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-112950",
      "aliases": [
        "CVE-2026-112950"
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "scope": "UNCHANGED",
            "version": "3.1",
            "baseScore": 5.9,
            "attackVector": "NETWORK",
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
            "integrityImpact": "NONE",
            "userInteraction": "NONE",
            "attackComplexity": "HIGH",
            "availabilityImpact": "NONE",
            "privilegesRequired": "NONE",
            "confidentialityImpact": "HIGH"
          }
        }
      ],
      "affected": [
        {
          "vendor": "vitest-dev",
          "product": "vitest",
          "versions": [
            {
              "status": "affected",
              "version": ">= 4.1.11, < 4.1.12"
            },
            {
              "status": "affected",
              "version": ">= 5.0.0-rc.2, < 5.0.3"
            }
          ]
        },
        {
          "vendor": "@vitest",
          "product": "mocker",
          "versions": [
            {
              "status": "affected",
              "version": ">= 4.1.11, < 4.1.12"
            },
            {
              "status": "affected",
              "version": ">= 5.0.0-rc.2, < 5.0.3"
            }
          ]
        }
      ],
      "modified": "2026-10-28T14:04:58.744Z",
      "provider": "cve",
      "references": [
        "https://github.com/vitest-dev/vitest/security/advisories/GHSA-xp26-3454-mjgp",
        "https://github.com/vitest-dev/vitest/commit/15cc006aa9f8683dc5f7e895d011fa7dc751ce35",
        "https://github.com/vitest-dev/vitest/commit/b825313243dc55757e8d7c0f9e7a792135e13473",
        "https://github.com/vitest-dev/vitest/releases/tag/v4.1.12",
        "https://github.com/vitest-dev/vitest/releases/tag/v5.0.3"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CISA ADP Vulnrichment",
            "metrics": [
              {
                "other": {
                  "type": "ssvc",
                  "content": {
                    "id": "CVE-2026-112950",
                    "role": "CISA Coordinator",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "version": "2.0.3",
                    "timestamp": "2026-10-28T14:04:50.974371Z"
                  }
                }
              }
            ],
            "references": [
              {
                "url": "https://github.com/vitest-dev/vitest/security/advisories/GHSA-xp26-3454-mjgp",
                "tags": [
                  "exploit"
                ]
              }
            ],
            "providerMetadata": {
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP",
              "dateUpdated": "2026-10-28T14:04:58.744Z"
            }
          }
        ],
        "cna": {
          "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
          "shortName": "GitHub_M",
          "dateUpdated": "2026-10-20T15:21:32.396Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-112950",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 447320,
  "published_at": "2026-10-20T15:21:32.396+00:00"
}