CVE-2026-100721
Last modified
CVE-2026-100721 is a critical-severity vulnerability rated 9/10 on the CVSS scale. 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.
Description
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.
Metrics
Weakness Enumeration
References
Timeline
- Published
- Last Modified
- Status
- Deferred
Frequently Asked Questions
What is CVE-2026-100721?
How severe is CVE-2026-100721?
How do I fix CVE-2026-100721?
How Strix Helps
- Uncovering a hidden BOLA in Appsmith's snapshot logicStrix autonomously discovered a BOLA/IDOR vulnerability in Appsmith's snapshot deletion path.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-100716Froxlor is a server administration panel. In versions 2.3.10…9.9
- CVE-2026-100717froxlor is a server administration panel. In versions 2.3.10…9.9
- CVE-2026-100718Froxlor through 2.3.10 does not enforce the mail.allow_exter…7.1
- CVE-2026-100719Froxlor versions before 2.3.12 contain a credential disclosu…6.5
- CVE-2026-10072DreamMaker developed by Interinfo has an Arbitrary File Uplo…8.6
- CVE-2026-100720Froxlor 2.0.0 through 2.3.10 is vulnerable to stored cross-s…8.7
- CVE-2026-100722vm2 before 3.12.2 does not apply host-side Promise rejection…6.8
- CVE-2026-100723vm2 before 3.12.2 does not apply its Buffer backing-store ow…7.5
- CVE-2026-100724http4k (Maven package org.http4k:http4k-core) before 6.49.0.…5.4
- CVE-2026-100725http4k (Maven artifact org.http4k:http4k-core) before 6.48.0…6.5
- CVE-2026-10073DreamMaker developed by Interinfo has an Arbitrary File Read…8.7
- CVE-2026-100739A vulnerability was detected in mathurvishal CloudClassroom-…7.3
Are you affected by CVE-2026-100721?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST
