CVE-2026-92939: vm2 crypto builtin loads attacker native code through setEngine

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• Not in CISA KEV, but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
• EPSS 0.6%, percentile 49: FIRST’s model estimates a 0.6% chance of exploitation activity in the next 30 days, higher than 49% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes vm2 (npm) >= 3.11.3, <= 3.11.6, fixed in 3.11.7. Check your lockfile, including transitive dependencies.
• Editorial verdict: Check exposure. vm2: 22 Critical Sandbox Escapes, Fixed in 3.12.2 — If anything outside your trust boundary can get code into vm2, upgrade to 3.12.2 today and plan to move that code out of process; if vm2 only runs your own code, upgrade on a normal cycle.

What it is

vm2 3.11.3 through 3.11.6 exposes the host Node.js crypto module to a NodeVM sandbox when the crypto builtin is allowed. The module is presented via a recursive read-only proxy, but its callable exports still execute with host-process authority. Sandboxed JavaScript can therefore call crypto.setEngine() with a filesystem path to an attacker-supplied native library (for example, one bundled in an untrusted plugin package already written to disk); OpenSSL asks the operating-system dynamic loader to load the file, and the library's constructor executes native code in the host process before engine-symbol validation rejects it. Exploitation requires only the crypto builtin and does not require fs, process, module, childprocess, workerthreads, vm, or inspector access, resulting in a sandbox escape and arbitrary native code execution. Fixed in 3.11.7.

From the GitHub advisory

Summary

vm2 3.11.6 exposes the host crypto module to a NodeVM when that single builtin is allowed. The module is presented through a read-only bridge, but its functions still execute with host-process authority. crypto.setEngine() accepts a filesystem path and asks OpenSSL to dynamically load the referenced native library.

An attacker whose untrusted plugin package contains a native library can therefore load that library into the host process by calling crypto.setEngine() from sandboxed JavaScript. The native library's constructor executes before OpenSSL finishes validating whether the file is a usable engine. Consequently, even the expected ERRCRYPTOENGINEUNKNOWN exception occurs only after arbitrary native code has already run.

The exploit requires only the crypto builtin. It does not require fs, process, module, childprocess, workerthreads, vm, inspector, unrestricted builtins, or vm2 nesting.

Details

Weakness type: CWE-114.

Product: vm2 (npm) · Assigned by: VulnCheck · Published: 2026-09-17

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: none
• Privileges required: low (any account)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation poc, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.62% probability of exploitation activity in the next 30 days; percentile 49.

Timeline

• 2026-08-17 — erroneo.us brief: vm2: 22 Critical Sandbox Escapes, Fixed in 3.12.2
• 2026-09-17 — CVE record last updated
• 2026-09-17 — CVE record published by VulnCheck
• 2026-10-01 — GitHub-reviewed advisory GHSA-46pr-c5wc-xffx published (critical)

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. GitHub Security Advisory (GHSA-46pr-c5wc-xffx) github.com

Vulnerability records

1. GitHub Advisory GHSA-46pr-c5wc-xffx github.com
2. CVE.org record CVE-2026-92939 cve.org
3. NVD entry CVE-2026-92939 nvd.nist.gov

Other references from the CVE record and advisory

1. VulnCheck Advisory: vm2 3.11.3 through 3.11.6 Native Code Execution via crypto.setEngine vulncheck.com
2. github.com github.com
3. github.com github.com

Critical npm advisories · Today’s Security Digest