{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.12.2"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "a0139cf6a7ad72a685420f53479a99fe385cf394"
            }
          ],
          "repo": "https://github.com/patriksimek/vm2",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-5h3f-q97h-ccvc"
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-863"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100721.json"
  },
  "details": "vm2 before 3.12.2 contains an authorization bypass in the NodeVM external-module resolver. When an embedder configures `require.external` with a custom resolver (and `context: 'host'`), `LegacyResolver.customResolve` in lib/resolver-compat.js records the resolved module directory in `this.externals` as `new RegExp('^' + escapeRegExp(resolvedPath))`, without requiring a path separator or end-of-string boundary. Untrusted guest code can therefore require the allowlisted module (e.g. `foo`) and then require the absolute path of a non-allowlisted sibling whose path merely shares the resolved prefix (e.g. `.../node_modules/foo2/index.js`); the sibling passes `isPathAllowedForModule` and is loaded through `hostRequire`, so its top-level code runs in the host process before the exports are wrapped with `vm.readonly`, resulting in a sandbox escape and arbitrary code execution in the host context.",
  "id": "CVE-2026-100721",
  "modified": "2026-09-29T03:30:52.840889789Z",
  "published": "2026-09-27T01:28:28.596Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100721.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/patriksimek/vm2/security/advisories/GHSA-5h3f-q97h-ccvc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-100721"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/vm2-before-3.12.2-authorization-bypass-via-custom-resolver"
    },
    {
      "type": "FIX",
      "url": "https://github.com/patriksimek/vm2/commit/6ac3916da84e060c403e407b6b6318fcc66b0e72"
    },
    {
      "type": "FIX",
      "url": "https://github.com/patriksimek/vm2/commit/91034466bfb7f56b95fd48083ec6ca36d058f164"
    },
    {
      "type": "FIX",
      "url": "https://github.com/patriksimek/vm2/commit/ab4ee7d803e8c80155e9eb3672226bddbca4aa9c"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
      "type": "CVSS_V4"
    }
  ],
  "summary": "vm2 before 3.12.2 Authorization Bypass via Custom Resolver"
}