CVE-2026-46621

Yamcs: Authenticated Remote Code Execution (RCE) via Jython Algorithm Code Injection

Published Jul 16, 2026 CVSS 3.1 · 9.1 Critical EPSS 1.1% KEV · Not listed
Description
Yamcs is a mission control framework. Prior to 5.12.7, the Yamcs script evaluation engine for Python algorithms dynamically compiled and evaluated user-controlled algorithm text using Jython through the JSR-223 ScriptEngine API without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing Python algorithm's logic through the mission database REST API and import and execute arbitrary Java classes such as java.lang.Runtime to achieve remote code execution on the underlying host operating system. This issue is fixed in versions 5.12.7 and 5.13.0, which disable algorithm editing by default.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-2g95-6x5q-xjwj Yamcs Vulnerable to Authenticated Remote Code Execution (RCE) via Jython Algorithm Code Injection
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 Yamcs
Yamcs yamcs
Vendors & Products Yamcs
Yamcs yamcs
Type Values Removed Values Added
Description Yamcs is a mission control framework. Prior to 5.12.7, the Yamcs script evaluation engine for Python algorithms dynamically compiled and evaluated user-controlled algorithm text using Jython through the JSR-223 ScriptEngine API without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing Python algorithm's logic through the mission database REST API and import and execute arbitrary Java classes such as java.lang.Runtime to achieve remote code execution on the underlying host operating system. This issue is fixed in versions 5.12.7 and 5.13.0, which disable algorithm editing by default.
Title Yamcs: Authenticated Remote Code Execution (RCE) via Jython Algorithm Code Injection
Weaknesses CWE-94
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 16, 2026, 6:00 PM
Reserved
May 15, 2026, 7:34 PM
Status
Analyzed
Published
Jul 16, 2026, 5:16 PM
Modified
Jul 20, 2026, 1:46 AM