CVE-2026-55376

heym Python Tool Sandbox Escape

Published Oct 13, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
Heym builds and runs agentic systems and business-process automations on self-hosted infrastructure. Prior to 0.0.40, an authenticated user who can create or edit a workflow with an Agent custom Python tool can bypass the blacklist-based sandbox in backend/app/services/python_tool_executor.py because allowed standard-library modules expose operating-system, process, and filesystem capabilities through public attributes that pass _safe_import() and _validate_code_safety(). The runner then executes the supplied tool with exec(), permitting commands and file operations as the backend application user; self-registration affects reachability, but portal triggering alone does not grant code control. This issue is fixed in 0.0.40.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Heymrun
Heymrun heym
Vendors & Products Heymrun
Heymrun heym
Type Values Removed Values Added
Description Heym builds and runs agentic systems and business-process automations on self-hosted infrastructure. Prior to 0.0.40, an authenticated user who can create or edit a workflow with an Agent custom Python tool can bypass the blacklist-based sandbox in backend/app/services/python_tool_executor.py because allowed standard-library modules expose operating-system, process, and filesystem capabilities through public attributes that pass _safe_import() and _validate_code_safety(). The runner then executes the supplied tool with exec(), permitting commands and file operations as the backend application user; self-registration affects reachability, but portal triggering alone does not grant code control. This issue is fixed in 0.0.40.
Title heym Python Tool Sandbox Escape
Weaknesses CWE-693
CWE-78
CWE-94
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 16, 2026, 10:00 PM
Reserved
Jun 16, 2026, 6:57 PM
Status
Deferred
Published
Oct 13, 2026, 4:17 PM
Modified
Oct 16, 2026, 10:17 PM