Authorization Bypass Vulnerability in vm2 by Patrik Simek
CVE-2026-100721

9.5CRITICAL

Key Information:

Vendor

Patriksimek

Status
Vm2
Vendor
CVE Published:
27 September 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-100721?

The vm2 package prior to version 3.12.2 introduces a critical vulnerability allowing unauthorized access through its external-module resolver. Specifically, when the require.external option is configured with a custom resolver and set to context: 'host', the vulnerability allows untrusted code to exploit the LegacyResolver.customResolve mechanism. This flaw permits the accidental loading of non-allowlisted modules alongside allowlisted ones, enabling sandbox escapes and the execution of arbitrary code within the host context. This exposes applications to significant risks, necessitating prompt updates to versions 3.12.2 or later.

Affected Version(s)

vm2 0 < 3.12.2

vm2 3.12.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-100721
Created by murrez

References

https://github.com/patriksimek/vm2/security/advisories/GH...
vendor-advisory
https://github.com/patriksimek/vm2/commit/6ac3916da84e060...
patch
https://github.com/patriksimek/vm2/commit/ab4ee7d803e8c80...
patch

CVSS V4

Score:
9.5
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

rexpository
.