CVE-2026-43999 | vm2: NodeVM builtin allowlist bypass via `module` builtin's `Module._load` allows sandbox escape

Exp

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.0, NodeVM's builtin allowlist can be bypassed when the module builtin is allowed (including via the '*' wildcard). The module builtin exposes Node's Module._load(), which loads any module by name directly in the host context, completely bypassing vm2's builtin restriction. This allows sandboxed code to load excluded builtins like child_process and achieve remote code execution. This vulnerability is fixed in 3.11.0.

Published: 2026-05-13 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-43999 is rated High Exploit Risk (71.5/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.67%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-43999

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-43999

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.16% 0.67% +0.51%
2 2026-05-15 0.14% 0.16% +0.01%
3 2026-05-14 — 0.14% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-43999

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.9 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.1 6.0 [email protected]

Weakness enumeration for CVE-2026-43999

GitHub Security Advisory for CVE-2026-43999

GHSA-947f-4v7f-x2v8 · Severity: critical · Ecosystem: npm — vm2 has a NodeVM builtin allowlist bypass via `module` builtin's `Module._load` that allows sandbox escape

Affected software / configurations for CVE-2026-43999

Vendor Product Version Raw CPE
vm2_project vm2 < 3.11.0 cpe:2.3:a:vm2_project:vm2:*:*:*:*:*:node.js:*:*

References for CVE-2026-43999

cvelogic Threat Intelligence