CVE-2026-44000Public exploitNetwork attack vector

Host object access via unwrapped Promise fulfillment

Published May 13, 2026 · Updated May 13, 2026

Sandbox boundary bypass in Patrik Simek vm2 before 3.11.0 allows attackers to read and mutate host objects through resolved Promises. The setup-sandbox.js fulfillment wrapper passes values through ensureThis(), which returns the original object when bridge.js finds no prototype mapping. Exploitation requires exposure of a host Promise resolving to a host object to sandboxed code, granting direct access only to reachable object state.

CVSS severity6.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sandbox boundary bypass in Patrik Simek vm2 before 3.11.0 allows attackers to read and mutate host objects through resolved Promises. The setup-sandbox.js fulfillment wrapper passes values through ensureThis(), which returns the original object when bridge.js finds no prototype mapping. Exploitation requires exposure of a host Promise resolving to a host object to sandboxed code, granting direct access only to reachable object state.

The record

CVE
CVE-2026-44000
Published
May 13, 2026
Updated
May 13, 2026
Vendor
Patrik Simek
Product
vm2
Classifications
CWE-693, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.11.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Patrik Simek · vm2version=< 3.11.0

Published CVSS scores

7.2NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-693Protection Mechanism Failure
T1059.007Command and Scripting Interpreter: JavaScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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