CVE-2026-55376Public exploitNetwork attack vectorHinoki check available

Authenticated code execution via Python sandbox escape

Published Oct 13, 2026 · Updated Oct 13, 2026

Sandbox escape in Heym before 0.0.40 allows remote authenticated users to execute commands via custom Python tools. In backend/app/services/python_tool_executor.py, _safe_import() and _validate_code_safety() permit public attributes of allowed modules that expose operating-system and filesystem capabilities before exec() runs supplied code. Exploitation requires workflow creation or editing access and grants command execution and file reads or writes as the backend application user; portal triggering alone does not grant code control.

CVSS severity8.8
High
EPSS probability0.36%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Sandbox escape in Heym before 0.0.40 allows remote authenticated users to execute commands via custom Python tools. In backend/app/services/python_tool_executor.py, _safe_import() and _validate_code_safety() permit public attributes of allowed modules that expose operating-system and filesystem capabilities before exec() runs supplied code. Exploitation requires workflow creation or editing access and grants command execution and file reads or writes as the backend application user; portal triggering alone does not grant code control.

The record

CVE
CVE-2026-55376
Published
Oct 13, 2026
Updated
Oct 13, 2026
Vendor
Heym
Product
Heym
Classifications
CWE-693, CWE-78, CWE-94, T1059.006
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.0.40

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Heym · Heymversion=< 0.0.40

Published CVSS scores

8.8GitHub_MCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-693Protection Mechanism Failure
CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CWE-94Improper Control of Generation of Code ('Code Injection')
T1059.006Python

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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