CVE-2026-92937: vm2: GHSA-m283-3h24-438v fix bypass leads to host RCE via call/apply indirection

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. 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 1.0%, percentile 63: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 63% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes vm2 (npm) = 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 3.11.6 is vulnerable to a sandbox escape leading to remote code execution in the host Node.js process. The fix for GHSA-m283-3h24-438v is incomplete: the bridge gate at lib/bridge.js:1624 identity-checks only the direct call target when deciding whether to rebuild/sanitise a rejected host Promise value. Registering the rejection handler through Function.prototype.call or .apply indirection (e.g., p.then.call(p, undefined, cb)) makes the intercepted target host Function.prototype.call, so the sanitiser never runs and the raw host error reaches sandbox code with its own properties intact. If an embedder exposes a host-realm Promise to the sandbox (an async host function bridged via the sandbox option, or a NodeVM external module's async method) and that Promise rejects with an Error carrying a non-primitive own property referencing a host object (for example err.detail = process), untrusted code in the sandbox obtains a fully functional proxy to that host object and can execute arbitrary commands with the privileges of the host process (e.g., e.detail.mainModule.require('childprocess').execSync(...)). The direct p.then(undefined, cb), bind, and Reflect.apply forms are correctly sanitised. Fixed in vm2 3.11.7.

From the GitHub advisory

Summary

Untrusted JavaScript run by vm2 can escape the sandbox and execute arbitrary commands in the host Node.js process when an embedder-exposed host Promise rejects. This is an incomplete fix for GHSA-m283-3h24-438v: the advisory's capability-bearing rejection rebuild runs only through this direct Promise-handler path, so call/apply indirection bypasses the protection it introduced. The bridge sanitises host rejection values before sandbox callbacks run, but the gate at lib/bridge.js:1624 identity-checks only the direct call target. Registering the rejection handler through Function.prototype.call indirection, p.then.call(p, undefined, cb), makes the intercepted target host Function.prototype.call, so the sanitiser never runs and the raw host error reaches the sandbox (lib/bridge.js:1639) without the rebuild that strips host references carried by its own properties (lib/setup-sandbox.js:2104). A rejection error whose own property references a powerful host object, for example err.detail = process, therefore reaches sandbox code as a fully functional proxy, and e.detail.mainModule.require('childprocess').execSync(...) executes with host privileges. The .apply form and a stacked call.call behave identically.

PoC

Save as poc.js and run node poc.js:

Observed output

Weakness type: CWE-94, CWE-693.

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: none (no login)
• 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 yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 1.03% probability of exploitation activity in the next 30 days; percentile 63.

Timeline

• 2026-08-17 — erroneo.us brief: vm2: 22 Critical Sandbox Escapes, Fixed in 3.12.2
• 2026-09-17 — CVE record published by VulnCheck
• 2026-09-18 — CVE record last updated
• 2026-10-01 — GitHub-reviewed advisory GHSA-647f-g98j-qq25 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-647f-g98j-qq25) github.com

Vulnerability records

1. GitHub Advisory GHSA-647f-g98j-qq25 github.com
2. CVE.org record CVE-2026-92937 cve.org
3. NVD entry CVE-2026-92937 nvd.nist.gov

Other references from the CVE record and advisory

1. VulnCheck Advisory: vm2 3.11.6 Remote Code Execution via Promise call/apply vulncheck.com
2. github.com github.com
3. github.com github.com

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