GHSA-9g8x-92q2-p28f
Fix: patriksimek/vm2@e1c48fcGHSA-9g8x-92q2-p28f is a CWE-668 vulnerability in vm2. O3 Security confirms whether GHSA-9g8x-92q2-p28f is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
NodeVM observability builtins leak host process and HTTP request data
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-9g8x-92q2-p28f.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
vm2npmDescription
Summary
NodeVM exposes some process-wide observability builtins when they are allowed through require.builtin.
The following builtins are not blocked by the dangerous builtin denylist:
diagnostics_channel
async_hooks
perf_hooks
These modules are process-wide, not sandbox-local. Sandboxed code can use them to observe host application data across the vm2 boundary.
Note: It is a host data exposure issue. The impact depends on whether the host application allows these builtins and uses HTTP, async request context, diagnostics channels, or performance marks in the same process.
Details
Non-denied builtins are exposed to the sandbox through lib/builtin.js:
builtins.set(key, special ? special : vm => vm.readonly(hostRequire(key)));
diagnostics_channel, async_hooks, and perf_hooks are not denied. These modules expose host process state rather than sandbox-local state.
Confirmed examples:
diagnostics_channellets sandboxed code subscribe to Node.js HTTP diagnostic channels such ashttp.server.request.start. The sandbox receives host HTTP request objects and can read headers such asAuthorizationor session tokens.async_hooks.executionAsyncResource()lets sandboxed code read the current hostAsyncResource. If the host stores request/user data on that resource, the sandbox can read it.perf_hooks.performance.getEntriesByType('mark')lets sandboxed code read host performance timeline entries.
PoC
Run from the vm2 repository root:
node poc/observability-builtins-info-leak.js
observability-builtins-info-leak.js
The PoC uses only the specific builtin being tested in each section.
It confirms:
diagnostics_channel: sandbox reads host HTTP request headers
async_hooks: sandbox reads host AsyncResource data
perf_hooks: sandbox reads host performance mark names
Example impact from the PoC:
authorization: Bearer HOST_HTTP_SECRET_...
x-session-token: HOST_HTTP_SECRET_...
These values are sent to a host HTTP server, but the sandbox reads them through diagnostics_channel.
Impact
An attacker who can run untrusted JavaScript inside NodeVM with affected builtin settings can observe data from the host process.
In a real application, this may expose HTTP request headers, authorization tokens, session tokens, request context values, user identifiers, or other sensitive diagnostics data from the host application or from other users.
Suggested fix
Treat process-wide observability modules as dangerous builtins for untrusted sandboxes.
At minimum, consider blocking:
diagnostics_channel
async_hooks
perf_hooks
These modules are not sandbox-local and can expose host process state across the vm2 boundary.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | vm2 | all versions | 3.11.4 |
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 3.11.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9g8x-92q2-p28f 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-9g8x-92q2-p28f 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-9g8x-92q2-p28f. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This vulnerability has been rated as Moderate for Red Hat Developer Hub and Red Hat Ansible Automation Platform. The vm2 sandbox exists as a transitive dependency in Red Hat Developer Hub and is only utilized during build time. The sandbox is therefore not exposed on the production code path. Exploitation of this…
Frequently Asked Questions
Is GHSA-9g8x-92q2-p28f in your dependencies?
O3 detects GHSA-9g8x-92q2-p28f across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.