GHSA-mmhj-4w6j-76h7 is a high-severity (CVSS 8) CWE-913 vulnerability in isolated-vm. O3 Security confirms whether GHSA-mmhj-4w6j-76h7 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Misuse of `Reference` and other transferable APIs may lead to access to nodejs isolate
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.
isolated-vmnpmDescription
Versions of isolated-vm before v4.0.0, and especially before v3.0.0, have API pitfalls which may make it easy for implementers to expose supposed secure isolates to the permissions of the main nodejs isolate.
Reference objects allow access to the underlying reference's full prototype chain. In an environment where the implementer has exposed a Reference instance to an attacker they would be able to use it to acquire a Reference to the nodejs context's Function object.
Similar application-specific attacks could be possible by modifying the local prototype of other API objects.
Access to NativeModule objects could allow an attacker to load and run native code from anywhere on the filesystem. If combined with, for example, a file upload API this would allow for arbitrary code execution.
To address these issues the following changes were made in v4.0.0:
- Documentation was updated with more explicit guidelines on building secure applications.
Referenceinstances will no longer follow prototype chains by default, nor will they invoke accessors or proxies.- All
isolated-vmAPI prototypes are now immutable. NativeModuleconstructor may only be invoked from a nodejs isolate.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | isolated-vm | all versions | 4.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for isolated-vm. 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 isolated-vm to 4.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mmhj-4w6j-76h7 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 GHSA-mmhj-4w6j-76h7 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 GHSA-mmhj-4w6j-76h7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-mmhj-4w6j-76h7 in your dependencies?
O3 detects GHSA-mmhj-4w6j-76h7 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.