---
title: "CVE-2026-55376: Heym - Command Injection"
description: "Heym < 0.0.40 contains a sandbox bypass caused by allowed standard-library modules exposing OS, process, and filesystem capabilities in python_tool_executor.py, letting authenticated users execute arbitrary code, exploit requires workflow creation or editing with Agent custom Python tool."
url: https://panop.io/threat-heartbeat/CVE-2026-55376/
---

# CVE-2026-55376 Heym - Command Injection

Heym < 0.0.40 contains a sandbox bypass caused by allowed standard-library modules exposing OS, process, and filesystem capabilities in python\_tool\_executor.py, letting authenticated users execute arbitrary code, exploit requires workflow creation or editing with Agent custom Python tool.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.36% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-55376)

## Details

Type

Command Injection

Impact

Remote Code Execution

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Published

13 October 2026

Updated

15 October 2026

Weakness

[CWE-78](https://cwe.mitre.org/data/definitions/78.html)

## Vendor fix

Update to version 0.0.40 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-55376](https://nvd.nist.gov/vuln/detail/CVE-2026-55376)
- [https://github.com/heymrun/heym/releases/tag/v0.0.40](https://github.com/heymrun/heym/releases/tag/v0.0.40)
- [https://github.com/heymrun/heym/security/advisories/GHSA-wcgw-9hfw-f6f2](https://github.com/heymrun/heym/security/advisories/GHSA-wcgw-9hfw-f6f2)
- [https://github.com/heymrun/heym/commit/b36d795c6ea841b8f1b511a0952e274487ee4ef3](https://github.com/heymrun/heym/commit/b36d795c6ea841b8f1b511a0952e274487ee4ef3)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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