Detect CVE-2026-47140 — vm2 Builtin Denylist Bypass via process/inspector Leads to Host RCE in Splunk
Detects exploitation of CVE-2026-47140, a critical sandbox escape in the npm vm2 package (versions <= 3.11.3). Attackers bypass the builtin module denylist using process and inspector/promises references to execute arbitrary code on the host Node.js process. CVSS 10.0. PoC is publicly available.
MITRE ATT&CK
SPL Detection Query
index=endpoint OR index=os sourcetype=WinEventLog:Security OR sourcetype=sysmon
| eval process_name=lower(process_name)
| where process_name IN ("node", "node.exe")
| eval cmdline_lower=lower(CommandLine)
| where cmdline_lower LIKE "%vm2%" OR cmdline_lower LIKE "%new vm%" OR cmdline_lower LIKE "%nodevm%"
| join type=left ProcessId [
search index=endpoint sourcetype=sysmon EventCode=3 Image="*node*"
| stats count AS net_connections, values(DestinationIp) AS dest_ips BY ProcessId
]
| join type=left ProcessId [
search index=endpoint sourcetype=sysmon EventCode=11 Image="*node*"
| where TargetFilename LIKE "%id_rsa%" OR TargetFilename LIKE "%.ssh%" OR TargetFilename LIKE "%shadow%" OR TargetFilename LIKE "%.env%"
| stats count AS sensitive_file_hits BY ProcessId
]
| where isnotnull(net_connections) OR isnotnull(sensitive_file_hits)
| eval risk=case(
isnotnull(sensitive_file_hits), "critical",
isnotnull(net_connections), "high",
true(), "medium"
)
| table _time, host, user, ProcessId, CommandLine, net_connections, dest_ips, sensitive_file_hits, risk
| sort -risk, -_timeDetects Node.js processes invoking vm2 that exhibit post-exploitation behaviors such as unexpected outbound connections or sensitive file access following a potential sandbox escape.
Data Sources
Required Sourcetypes
False Positives & Tuning
- Legitimate vm2-based sandboxing applications with outbound network requirements
- Developer workstations running vm2 unit tests alongside network-connected services
- Automated build systems that exercise vm2 as part of test suites
- Security tooling that uses vm2 for payload analysis with controlled networking
Other platforms for CVE-2026-47140
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1vm2 Sandbox Escape via inspector/promises — Host Code Execution
Expected signal: Sysmon/auditd will log: (1) node process launch with vm2 in path or arguments, (2) file creation event at /tmp/vm2_escape_poc.txt by the node process, (3) a child process or execSync call spawning sh/bash from within node
- Test 2vm2 Escape with Outbound Network Callback (Simulated C2 Beacon)
Expected signal: Network flow logs will show an outbound HTTP connection to example.com originating from the node process PID. EDR should capture the network connect event and correlate it to the parent node process with vm2 in its command line.
- Test 3vm2 Escape via process.binding — Enumerate Host Environment Secrets
Expected signal: File write event at /tmp/vm2_env_harvest.json attributed to node process. Process event showing node with potential vm2-related arguments. EDR may also capture the internal environment variable enumeration if it hooks process.env access.
References (5)
- https://github.com/patriksimek/vm2/security/advisories/GHSA-rp36-8xq3-r6c4
- https://github.com/patriksimek/vm2/commit/a1ed47a98d1cc36cb48c0d566d55889688e0b59b
- https://github.com/patriksimek/vm2/releases/tag/v3.11.4
- https://nvd.nist.gov/vuln/detail/CVE-2026-47140
- https://github.com/advisories/GHSA-rp36-8xq3-r6c4
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