Security Digest · Vulnerability record
CVE-2026-24120: VM2 Has Sandbox Breakout Through Promise Species
vm2 is an open source vm/sandbox for Node.js.
CVSS 9.8 Critical EPSS 0.9% · p59
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 0.9%, percentile 59: FIRST’s model estimates a 0.9% chance of exploitation activity in the next 30 days, higher than 59% 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) <= 3.10.3, fixed in 3.10.5. Check your lockfile, including transitive dependencies.
What it is
vm2 is an open source vm/sandbox for Node.js. Prior to version 3.10.5, the fix for CVE-2023-37466 is insufficient and can be circumvented allowing attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system. This issue has been patched in version 3.10.5.
From the GitHub advisory
Summary
The fix for https://github.com/patriksimek/vm2/security/advisories/GHSA-cchq-frgv-rjh5 is insufficient and can be circumvented allowing attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system.
Details
The fix for https://github.com/patriksimek/vm2/security/advisories/GHSA-cchq-frgv-rjh5 introduced the function resetPromiseSpecies https://github.com/patriksimek/vm2/blob/4b009c2d4b1131c01810c1205e641d614c322a29/lib/setup-sandbox.js#L35C7-L39. This function changes the species property of promise objects back to a known value. However, it uses the function [].includes and Object.defineProperty which can be overewritten to prevent the species from being changed.
PoC
Weakness type: CWE-693, CWE-94, CWE-807.
Product: vm2 (npm) · Assigned by: GitHub_M · Published: 2026-05-04
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| npm | vm2 | <= 3.10.3 | 3.10.5 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| patriksimek | vm2 | < 3.10.5 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_M | 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| redhat-SADP | 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: unchanged
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): 0.90% probability of exploitation activity in the next 30 days; percentile 59.
Timeline
- — CVE record published by GitHub_M
- — GitHub-reviewed advisory GHSA-qvjj-29qf-hp7p published (critical)
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-qvjj-29qf-hp7p github.com
- CVE.org record CVE-2026-24120 cve.org
- NVD entry CVE-2026-24120 nvd.nist.gov
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
- access.redhat.com access.redhat.com
- RHBZ#2466529 bugzilla.redhat.com
- security.access.redhat.com security.access.redhat.com
- github.com github.com