CVE-2026-43997Public exploitNetwork attack vector

Host code execution via cross-realm symbol extraction

Published May 13, 2026 · Updated May 13, 2026

Code injection in Patrik Simek vm2 before 3.11.0 allows remote attackers to execute arbitrary code on the host through sandboxed JavaScript. HostObject.getOwnPropertySymbols exposes a host-realm inspection symbol, whose callback supplies a host Function constructor that sandboxed code invokes. Exploitation requires an application to run attacker-controlled code in vm2; a successful escape grants the code the host process's privileges.

CVSS severity10.0
Critical
EPSS probability0.98%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in Patrik Simek vm2 before 3.11.0 allows remote attackers to execute arbitrary code on the host through sandboxed JavaScript. HostObject.getOwnPropertySymbols exposes a host-realm inspection symbol, whose callback supplies a host Function constructor that sandboxed code invokes. Exploitation requires an application to run attacker-controlled code in vm2; a successful escape grants the code the host process's privileges.

The record

CVE
CVE-2026-43997
Published
May 13, 2026
Updated
May 13, 2026
Vendor
Patrik Simek
Product
vm2
Classifications
CWE-94, 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

10.0GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

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.

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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-94Improper Control of Generation of Code ('Code Injection')
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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