---
id: CVE-2026-46621
title: Yamcs is a mission control framework
summary: >-
  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 e…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-94
vendor: spaceapplications
product: yamcs
affected:
  - yamcs < 5.12.7
patched:
  - yamcs 5.12.7
published: '2026-07-16'
updated: '2026-07-20'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-46621'
references:
  - url: >-
      https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011
    label: security-advisories@github.com
  - url: >-
      https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992
    label: security-advisories@github.com
  - url: 'https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7'
    label: security-advisories@github.com
  - url: 'https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0'
    label: security-advisories@github.com
  - url: 'https://github.com/yamcs/yamcs/security/advisories/GHSA-2g95-6x5q-xjwj'
    label: security-advisories@github.com
  - url: 'https://github.com/yamcs/yamcs/security/advisories/GHSA-2g95-6x5q-xjwj'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.01116
epssPercentile: 0.64713
ingestedAt: '2026-07-20T02:36:03.217Z'
---

## Overview

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.

## Affected

- `yamcs < 5.12.7`

## Remediation

Upgrade past the affected range:

- `yamcs 5.12.7`