CVE-2026-43998
HIGHCVE-2026-43998 is a high-severity (CVSS 8.5) remote code execution vulnerability in vm2. O3 Security confirms whether CVE-2026-43998 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
vm2: NodeVM require.root bypass via symlink traversal allows sandbox escape
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
vm2npmDescription
vm2 is an open source vm/sandbox for Node.js. In 3.10.5, NodeVM's require.root path restriction can be bypassed using filesystem symlinks, allowing sandboxed code to load modules from outside the allowed root directory in host context. Because path validation uses path.resolve() (which does not dereference symlinks) but module loading uses Node's native require() (which does), an attacker can load arbitrary host-realm modules and achieve remote code execution. This vulnerability is fixed in 3.11.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | vm2 | ≥ 3.10.5&&< 3.11.0 | 3.11.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vm2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update vm2 to 3.11.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-43998 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-43998 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-43998. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-43998 in your dependencies?
O3 detects CVE-2026-43998 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.