Vulnerability in Patriksimek Vm2

CVE-2026-92954

vm2 is a sandbox library for running untrusted JavaScript in Node.js. In versions >= 3.10.0 and <= 3.11.7, Promises returned from the host realm into the sandbox are not marked as handled at the bridge boundary; only Promises created inside the sandbox are wrapped with a rejection-swallowing handler (lib/setup-sandbox.js), and the bridge only installs host-side rejection sanitizers when sandbox code calls .then/.catch/.finally. As a result, code running in the sandbox can invoke a host function that returns a rejected Promise (for example events.once() exposed via the NodeVM events builtin, or any embedder-provided Promise-returning API) and simply ignore the return value, leaving the host Promise unhandled so that Node.js's default unhandled-rejection behavior terminates the host process. This is an incomplete fix of GHSA-hw58-p9xv-2mjh. The issue is fixed in version 3.11.8.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-92954?
CVE-2026-92954 is a high-severity vulnerability in Patriksimek Vm2, classified under CWE-248. CVSS score: 8.6/10. Published 2026-09-17.
How severe is CVE-2026-92954?
High severity. CVSS v3 base score is 8.6 out of 10.