CVE-2026-92940: CVE-2026-92940: Host-Realm Credential Exposure and Socket Hijacking via globalAgent in vm2

Vulnerability Overview

CVE‑2026‑92940 describes a critical vulnerability in the Node.js sandbox library vm2. Sandboxed code can retrieve the process‑wide http.globalAgent and https.globalAgent singletons. By attaching event listeners to these host‑realm emitters, sandboxed code can intercept host‑realm network requests, capturing sensitive Authorization headers and hijacking active TLSSocket streams.

TL;DR - A sandbox escape in vm2 (versions 3.11.3 to 3.11.6) allows untrusted code to access and hook the host process‑wide http/https globalAgent. This enables unauthenticated attackers to steal sensitive headers (like Bearer tokens) and hijack active sockets during unrelated host‑realm requests.

Technical Details

• CWE ID: CWE‑668 - Exposure of Resource to Wrong Sphere
• Attack Vector: Network (AV:N)
• CVSS v3.1 Score: 10.0 (Critical)
• EPSS Score: 0.00474 (Percentile: 38.70%)
• Impact: Host Credential Disclosure & Transport Socket Hijacking
• Exploit Status: Proof‑of‑Concept (PoC) available via official regression test suite
• CISA KEV Status: Not Listed

Affected Systems

• vm2 (npm package)
  • Versions ≥ 3.11.3, ≤ 3.11.6 (Fixed in: 3.11.7)

Code Analysis

Commit: aa146a7 - Implement member‑level sanitization for built‑in HTTP and HTTPS agents to prevent globalAgent exposure inside the sandbox context.

--- a/lib/builtin.js
+++ b/lib/builtin.js
+// Adds sanitization and overwrites request/get to use sandboxed agents

Exploit Details

• GitHub Security Advisory: Details the vulnerability report, the architectural mechanism of the escape, and provides the reproduction script used as verification.

Mitigation Strategies

• Upgrade vm2 to version 3.11.7 or newer to apply member‑level neutralization on built‑in HTTP/HTTPS modules.
• Disable the 'http' and 'https' built‑in modules inside the NodeVM configuration settings to remove the attack vector entirely.
• Implement outbound network requests outside of the sandbox boundary using a strictly validated custom host‑realm API rather than exposing native raw network modules.
• Transition application architectures away from vm2 to modern isolated runtimes, such as isolated‑vm or VM containers.

Remediation Steps

• Locate and audit package.json and project lockfiles for vm2 references within versions 3.11.3 and 3.11.6.
• Run 'npm install vm2@3.11.7 ' or 'yarn upgrade vm2@3.11.7 ' to deploy the patched library version.
• Review initialization scripts of NodeVM to ensure that 'http' and 'https' are absent from the require.builtin array.
• Validate the fix by executing the official regression test to ensure host globalAgent is no longer reachable from the sandbox environment.

References

• GHSA‑h85j‑hv3c‑qfgq Security Advisory
• VulnCheck Vulnerability Report
• Official Patch Commit
• vm2 v3.11.7 Release Tag
• NVD CVE‑2026‑92940 Details
• Read the full report for CVE‑2026‑92940 on our website for more details including interactive diagrams and full exploit analysis.