Summary
vm2 leaks absolute host filesystem paths to sandbox code via error stack formatting
Attacker-controlled code can trigger a host-realm syntax error and read its stack through the vm2 bridge. Host-realm stack formatting bypasses the sandbox-side redaction, so the returned value exposes absolute paths from vm2, Node.js internals, and the embedding application. Default VM and NodeVM configurations are affected without requiring special options.
PoC
A default-configured VM runs attacker-supplied code. Calling eval with deliberately malformed source makes the host-side source transformer throw a SyntaxError; reading .stack on the caught error exposes the host call stack to the sandbox.
const { VM } = require("vm2");
console.log(new VM().run(`
var s; try { eval("@@@ catch") } catch (e) { s = e.stack }
s;
`));
Observed output
SyntaxError: Unexpected character '@'
at makeNiceSyntaxError (.../lib/transformer.js:41:16)
at transformer (.../lib/transformer.js:116:8)
at Object.transformAndCheck (.../lib/vm.js:76:14)
at Object.apply (.../lib/setup-sandbox.js:2585:16)
at VM.run (.../lib/vm.js:529:16)
The stack string returned to the sandbox contains absolute host paths for lib/transformer.js, lib/vm.js, lib/setup-sandbox.js, Node internals, and the embedding application's own source file.
Impact
Sandboxed code running under the default new VM() or new NodeVM() configuration can read absolute filesystem paths of the embedding application's source tree plus host function names, bypassing the host-path redaction added for GHSA-v27g-jcqj-v8rw. On a multi-tenant code-runner this discloses deployment layout such as /home/app/... or /var/task/..., useful for fingerprinting and for chaining into further attacks. The bridge forwards .stack reads to the host-realm formatter (lib/bridge.js:1482), so the sandbox-side stack redaction never runs; the leak does not require special configuration and persists when string eval is disabled, because the host-side transformer throws before eval is handled. Information disclosure only, no code execution.
CVE-2026-92936 has a CVSS score of 5.8 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.11.7); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-92936? CVE-2026-92936 is a medium-severity security vulnerability in vm2 (npm), affecting versions >= 3.11.0, <= 3.11.6. It is fixed in 3.11.7.
- How severe is CVE-2026-92936? CVE-2026-92936 has a CVSS score of 5.8 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of vm2 are affected by CVE-2026-92936? vm2 (npm) versions >= 3.11.0, <= 3.11.6 is affected.
- Is there a fix for CVE-2026-92936? Yes. CVE-2026-92936 is fixed in 3.11.7. Upgrade to this version or later.
- Is CVE-2026-92936 exploitable, and should I be worried? Whether CVE-2026-92936 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-92936 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-92936? Upgrade
vm2to 3.11.7 or later.