CVE-2026-93604

vm2 through 3.12.0 exposes Node.js's crypto.setFips() function to untrusted guest code when an embedder explicitly allow

score 0MEDIUM 6.9

Summary

vm2 through 3.12.0 exposes Node.js's crypto.setFips() function to untrusted guest code when an embedder explicitly allowlists the crypto builtin for a NodeVM (require.builtin: ['crypto']). The builtin sanitizer (sanitizeCryptoModule in lib/builtin.js) replaces crypto.setEngine but leaves crypto.setFips callable, and the readonly wrapper used to expose the host module does not localize side effects of forwarded host functions. Guest code can therefore call crypto.setFips() to change the FIPS mode of the entire host process; the modified mode is subsequently observed by trusted host code (crypto.getFips() changed from 0 to 1 in the reported test), crossing the NodeVM isolation boundary. Fixed in vm2 3.12.1.

Published 2026-09-18 · first seen here 2026-10-10

Analysis & write-ups

No technical write-up from a research team yet. Contact Zero checks Unit 42, Google/Mandiant, Microsoft, Talos, CrowdStrike, Rapid7, watchTowr and others several times a day, plus NVD and CISA reference links.

Where it shows in your logs

Server or web application · Local privilege escalation medium confidence

What to look for

SYSTEM or root processes started from a non-admin user's session
Known exploit tool names or unsigned binaries run from user-writable folders (Temp, Downloads, /tmp)
The application's process (w3wp.exe, java, tomcat, node, php-fpm, httpd, python) starting shells or LOLBins (cmd, powershell, sh, bash, curl, wget, certutil)
New script files in web roots (.jsp, .aspx, .php): a web shell
Requests to unusual URLs on the application from internet IPs right before any of the above
Outbound connections from the server to new external IPs

Data sources

Web server and WAF logs · ATT&CK DS0015 Application Log Content

Sentinel: W3CIISLogAppServiceHTTPLogsAzureDiagnostics (Application Gateway / Front Door WAF)_Im_WebSession
Splunk: Web.Webms:iis:autoaccess_combinedWAF / proxy sourcetypes
CrowdStrike: Falcon Next-Gen SIEM: third-party web / WAF / proxy logs

Process creation · ATT&CK DS0009 Process Creation

Sentinel: DeviceProcessEventsSecurityEvent (4688)Sysmon Event ID 1_Im_ProcessCreate
Splunk: Endpoint.ProcessesXmlWinEventLog:Microsoft-Windows-Sysmon/OperationalWinEventLog:Security (4688)
CrowdStrike: ProcessRollup2SyntheticProcessRollup2

File creation · ATT&CK DS0022 File Creation

Sentinel: DeviceFileEventsSysmon Event ID 11_Im_FileEvent
Splunk: Endpoint.FilesystemSysmon Event ID 11
CrowdStrike: NewExecutableWrittenNewScriptWritten*FileWritten events

Network connections · ATT&CK DS0029 Network Connection Creation / Network Traffic Flow

Sentinel: DeviceNetworkEventsCommonSecurityLog (firewall)_Im_NetworkSession
Splunk: Network_Traffic.All_TrafficFirewall sourcetypes (pan:traffic, fortigate_traffic, cisco:asa)
CrowdStrike: NetworkConnectIP4NetworkReceiveAcceptIP4NetworkConnectIP6

Account and group changes · ATT&CK DS0002 User Account Creation / Modification

Sentinel: SecurityEvent (4720, 4728, 4732, 4756)AuditLogsIdentityDirectoryEvents
Splunk: Change.All_Changes (Account_Management)WinEventLog:Security (4720, 4732)
CrowdStrike: UserAccountCreatedUserAccountAddedToGroup