CVE-2026-100864

heym before 0.0.91 Remote Code Execution via Expression Engine

Published Sep 27, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
heym before 0.0.91 contains a sandbox escape vulnerability in the expression engine's DotList map/filter and fallback resolver that allows authenticated users to execute arbitrary Python code. Attackers can craft workflow expressions using dunder attribute access through item expressions or the fallback resolver to access os.system and execute commands as the backend process.

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 before 0.0.91 contains a sandbox escape vulnerability in the expression engine's DotList map/filter and fallback resolver that allows authenticated users to execute arbitrary Python code. Attackers can craft workflow expressions using dunder attribute access through item expressions or the fallback resolver to access os.system and execute commands as the backend process.
Title heym before 0.0.91 Remote Code Execution via Expression Engine
Weaknesses 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'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 28, 2026, 4:04 PM
Reserved
Sep 27, 2026, 12:20 AM
Status
Deferred
Published
Sep 27, 2026, 2:17 AM
Modified
Sep 28, 2026, 8:57 PM