{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-100721","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-09-26T02:40:56.226Z","datePublished":"2026-09-27T01:28:28.596Z","dateUpdated":"2026-09-27T01:28:28.596Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-09-27T01:28:28.596Z"},"datePublic":"2026-09-08T00:00:00.000Z","title":"vm2 before 3.12.2 Authorization Bypass via Custom Resolver","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Incorrect Authorization","cweId":"CWE-863","type":"CWE"}]}],"affected":[{"vendor":"patriksimek","product":"vm2","defaultStatus":"unaffected","packageURL":"pkg:npm/vm2","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"3.12.2"},{"version":"3.12.2","status":"unaffected","versionType":"semver"}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"HIGH","baseScore":9.5,"baseSeverity":"CRITICAL"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":9,"baseSeverity":"CRITICAL"}}],"references":[{"url":"https://github.com/patriksimek/vm2/security/advisories/GHSA-5h3f-q97h-ccvc","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-5h3f-q97h-ccvc)"},{"url":"https://github.com/patriksimek/vm2/commit/6ac3916da84e060c403e407b6b6318fcc66b0e72","tags":["patch"],"name":"Patch Commit"},{"url":"https://github.com/patriksimek/vm2/commit/ab4ee7d803e8c80155e9eb3672226bddbca4aa9c","tags":["patch"],"name":"Patch Commit"},{"url":"https://github.com/patriksimek/vm2/commit/91034466bfb7f56b95fd48083ec6ca36d058f164","tags":["patch"],"name":"Patch Commit"},{"name":"VulnCheck Advisory: vm2 before 3.12.2 Authorization Bypass via Custom Resolver","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/vm2-before-3.12.2-authorization-bypass-via-custom-resolver"}],"credits":[{"lang":"en","value":"rexpository","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}}}}