vm2: Host File Path Disclosure via Stack Trace Information Leak

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, vm2's CallSite wrapper class (intended as a safe wrapper for V8's native CallSite) blocks getThis() and getFunction() to prevent host object leakage, but allows getFileName() to return unsanitized host absolute paths. Any sandboxed code can extract the full directory structure, library paths, and framework versions of the host server. This vulnerability is fixed in 3.11.0.

Source published

13 May 2026 17:29:42 UTC

Source modified

14 May 2026 18:23:31 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, vm2's CallSite wrapper class (intended as a safe wrapper for V8's native CallSite) blocks getThis() and getFunction() to prevent host object leakage, but allows getFileName() to return unsanitized host absolute paths. Any sandboxed code can extract the full directory structure, library paths, and framework versions of the host server. This vulnerability is fixed in 3.11.0.

Source published

May 13, 2026, 5:29:42 PM (timezone not stated)

Source modified

May 14, 2026, 6:23:31 PM (timezone not stated)

Observed here

7 Nov 2026 09:37:48 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, vm2's CallSite wrapper class (intended as a safe wrapper for V8's native CallSite) blocks getThis() and getFunction() to prevent host object leakage, but allows getFileName() to return unsanitized host absolute paths. Any sandboxed code can extract the full directory structure, library paths, and framework versions of the host server. This vulnerability is fixed in 3.11.0.

Source published

13 May 2026 18:16:16 UTC

Source modified

26 Oct 2026 17:10:03 UTC

Observed here

27 Oct 2026 11:12:09 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

### Summary vm2's `CallSite` wrapper class (intended as a safe wrapper for V8's native CallSite) blocks `getThis()` and `getFunction()` to prevent host object leakage, but allows `getFileName()` to return unsanitized host absolute paths. Any sandboxed code can extract the full directory structure, library paths, and framework versions of the host server. ### Details In `lib/setup-sandbox.js:436-466`, the `CallSite` class overrides `getThis()` and `getFunction()` with `undefined` to prevent host object references from leaking into the sandbox. However, the following methods pass through unsanitized values from the original V8 CallSite object: - `getFileName()` — returns host absolute paths like `/app/node_modules/vm2/lib/vm.js` - `getLineNumber()`, `getColumnNumber()` — exact source locations - `getFunctionName()`, `getMethodName()`, `getTypeName()` — internal function names Two exploitation paths exist: 1. **Default `error.stack`**: `new Error().stack` includes host frame paths in the formatted string 2. **Custom `prepareStackTrace`**: Attacker can set `Error.prepareStackTrace` to directly call `getFileName()` on each CallSite, extracting a clean list of all host paths ### PoC **Library-level PoC (Node.js script — primary):** ```javascript const { VM } = require("vm2"); const vm = new VM(); // Path A — Default error.stack const result1 = vm.run(`try { null.x; } catch(e) { e.stack }`); console.log(result1); // Output includes: /app/node_modules/vm2/lib/vm.js:289:18 // /app/src/server.js:49:20 // Path B — prepareStackTrace extraction const result2 = vm.run(` Error.prepareStackTrace = function(e, sst) { return sst.map(function(s) { return s.getFileName(); }).join(", "); }; new Error().stack `); console.log(result2); // Output: vm.js, node:vm, /app/node_modules/vm2/lib/vm.js, /app/src/sandbox.js, ... ``` **HTTP demonstration:** ```bash # Default error.stack curl -s -X POST http://localhost:3000/api/execute \ -H "Content-Type: application/json" \ -d '{"code":"try { null.x; } catch(e) { e.stack }"}' # Result includes host paths: /app/src/server.js, /app/node_modules/express/... # prepareStackTrace extraction curl -s -X POST http://localhost:3000/api/execute \ -H "Content-Type: application/json" \ -d '{"code":"Error.prepareStackTrace = function(e, sst) { return sst.map(function(s) { return s.getFileName(); }).join(\", \"); }; new Error().stack"}' # Result: /app/node_modules/vm2/lib/vm.js, /app/src/sandbox.js, /app/src/server.js, ... ``` ### Impact - **Information Disclosure**: Host directory structure, library paths, framework versions, and internal architecture are exposed to sandboxed code. - **Attack Chain**: Leaked paths enable precise targeting for other vulnerabilities. - **Scope**: All applications using vm2. No special configuration required.

Source published

7 May 2026 04:30:10 UTC

Source modified

14 May 2026 20:52:41 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

Publisher rating · MODERATE