Is CVE-2026-100723 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-100723 being exploited in the wild.

How severe is CVE-2026-100723?

Critical severity, with a CVSS score of 10, published 27 September 2026.

Which products and versions are affected?

vm2 (npm) <= 3.12.1, SEMVER:introduced=0,fixed=3.12.2; Patrik Simek Vm2 before 3.12.2.

Is there a fix for CVE-2026-100723?

Yes. vm2 (npm): upgrade to 3.12.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-100723 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-100723?

Check whether you run vm2 (npm) or Patrik Simek Vm2 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-100723: vm2 sandbox escape via Buffer backing-store ownership bypass

Q: Which products and versions are affected?

vm2 (npm) <= 3.12.1, SEMVER:introduced=0,fixed=3.12.2; Patrik Simek Vm2 before 3.12.2.

Q: Is there a fix for CVE-2026-100723?

Yes. vm2 (npm): upgrade to 3.12.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-100723 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2026-100723?

Check whether you run vm2 (npm) or Patrik Simek Vm2 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-100723 · Severity: critical · CVSS 10 · Published 2026-09-27

vm2 is a Node.js library that runs untrusted code in an isolated sandbox. When an application exposes Node's zlib module, a vulnerability allows sandbox code to construct a full-width view of Node's shared buffer pool, potentially reading and modifying sensitive data in the host process. This breaks the sandbox isolation and allows attackers to steal secrets and corrupt host memory.

Technologies: vm2 (npm), Patrik Simek Vm2. Vendors: npm, Patrik Simek.

Quick answers

Is CVE-2026-100723 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-100723 being exploited in the wild.
How severe is CVE-2026-100723?: Critical severity, with a CVSS score of 10, published 27 September 2026.
Which products and versions are affected?: vm2 (npm) <= 3.12.1, SEMVER:introduced=0,fixed=3.12.2; Patrik Simek Vm2 before 3.12.2.
Is there a fix for CVE-2026-100723?: Yes. vm2 (npm): upgrade to 3.12.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-100723 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-100723?: Check whether you run vm2 (npm) or Patrik Simek Vm2 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

vm2 (npm): upgrade to 3.12.2 or later
```
npm install vm2@3.12.2
```

Technical details

The vulnerability exists in vm2 before 3.12.2 where Buffer objects returned from host builtin modules (e.g., zlib.deflateSync) bypass the backing-store ownership invariant. These buffers are backed by Node's shared small-buffer pool; untrusted code can access the entire pool via the .buffer property and create a full-width ArrayBuffer view, reading and modifying unrelated host buffers across the sandbox boundary. The fix applies a depooling mechanism at all sandbox-facing buffer factories to ensure buffers returned to sandbox code own their entire backing store.

Affected products

Patrik Simek vm2 before 3.12.2

Identifiers

CVE-2026-100723
GHSA-489w-w794-jq94

Timeline

2026-09-27: disclosed
2026-08-22: patched: Fix committed; released in version 3.12.2

References

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