GHSA-9538-79j2-h62h: Duplicate Advisory `allowAsync: False` Can Be Bypassed Vulnerability

HIGH
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CVSS 7.1
CWE-693
Published
Advisory Summary

GHSA-9538-79j2-h62h is a HIGH (CVSS 7.1) `allowasync: false` can be bypassed vulnerability (CWE-693: Protection Mechanism Failure) affecting Duplicate Advisory libraries in the npm ecosystem. The issue involves `allowasync: false` can be bypassed through promise thenable assimilation in vm and nodevm. Remediation is available in the latest vendor maintenance releases.

GHSA-9538-79j2-h62h at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-9538-79j2-h62h
Severity HIGH
CVSS v3.1 Base Score 7.1
CWE Classification CWE-693: Protection Mechanism Failure
Affected Product Duplicate Advisory
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity Low (I:L)
Availability High (A:H)

How to Fix GHSA-9538-79j2-h62h

To remediate this vulnerability, upgrade all affected Duplicate Advisory dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

vm2 fixed: Latest secure release 
npm install vm2@Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls vm2

How to Check if You Are Affected

To determine whether your Node.js application is affected by GHSA-9538-79j2-h62h, inspect your project dependencies using npm:

npm ls vm2

Analyze the terminal output to locate any version of Duplicate Advisory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The npm ls vm2 command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-693: Protection Mechanism Failure, where the product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. In Duplicate Advisory, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-f8gf-w286-fmq2. This link is maintained to preserve external references. ## Original Description vm2 before 3.11.8 does not fully enforce the allowAsync: false option in VM and NodeVM. While localPromise.prototype.then is replaced with a handler that throws 'Async not available', the sandbox's Promise static methods (Promise.resolve, Promise.all, Promise.race, Promise.any, and Promise.allSettled) still assimilate attacker-supplied thenables: native promise resolution performs PromiseResolveThenableJob and invokes the sandboxed code's then method in a microtask without passing through the patched then, so the async restriction is never applied. As a result, sandboxed script can schedule work that runs after VM.run() or NodeVM.run() has returned and outside the configured timeout, continuing to execute after the host believes execution is complete.

GHSA-9538-79j2-h62h Affected Duplicate Advisory Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
vm2
npm/vm2
npm
≤ 3.11.7

References

GitHub Advisory / Wiki ADVISORY
https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2
NVD — GHSA-9538-79j2-h62h NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-92959
www.vulncheck.com/advisories/vm2-befo... WEB
https://www.vulncheck.com/advisories/vm2-before-3.11.8-allowasync-bypass-via-promise-thenable

Frequently Asked Questions

What is GHSA-9538-79j2-h62h?
GHSA-9538-79j2-h62h is a security vulnerability in Duplicate Advisory involving `allowAsync: false` can be bypassed through Promise thenable assimilation in VM and NodeVM under CWE-693: Protection Mechanism Failure.
Which Duplicate Advisory versions are affected?
Affected versions include releases prior to current release patches across affected packages: vm2.
What version fixes GHSA-9538-79j2-h62h?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is vm2 affected?
Yes, vm2 is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of GHSA-9538-79j2-h62h?
GHSA-9538-79j2-h62h has a CVSS v3.1 base score of 7.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H.
What CWE is associated with GHSA-9538-79j2-h62h?
GHSA-9538-79j2-h62h is classified under CWE-693: Protection Mechanism Failure (The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.).
How can I check npm dependencies for GHSA-9538-79j2-h62h?
Run the dependency tree command: 'npm ls vm2'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9538-79j2-h62h",
  "modified" : "2026-10-05T22:47:22Z",
  "published" : "2026-09-17T15:32:16Z",
  "withdrawn" : "2026-10-05T22:47:22Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: `allowAsync: false` can be bypassed through Promise thenable assimilation in VM and NodeVM",
  "details" : "## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-f8gf-w286-fmq2. This link is maintained to preserve external references.\n\n## Original Description\nvm2 before 3.11.8 does not fully enforce the allowAsync: false option in VM and NodeVM. While localPromise.prototype.then is replaced with a handler that throws 'Async not available', the sandbox's Promise static methods (Promise.resolve, Promise.all, Promise.race, Promise.any, and Promise.allSettled) still assimilate attacker-supplied thenables: native promise resolution performs PromiseResolveThenableJob and invokes the sandboxed code's then method in a microtask without passing through the patched then, so the async restriction is never applied. As a result, sandboxed script can schedule work that runs after VM.run() or NodeVM.run() has returned and outside the configured timeout, continuing to execute after the host believes execution is complete.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "vm2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "3.11.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/patriksimek/vm2/security/advisories/GHSA-f8gf-w286-fmq2"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-92959"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/vm2-before-3.11.8-allowasync-bypass-via-promise-thenable"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-693" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-05T22:47:22Z",
    "nvd_published_at" : "2026-09-17T14:18:02Z"
  }
}