---
id: CVE-2026-46562
title: Yamcs is a mission control framework
summary: >-
  Yamcs is a mission control framework. Prior to 5.12.7, the Nashorn
  ScriptEngine used to evaluate user-supplied JavaScript algorithm text in
  yamcs-core/src/main/java/org/yamcs/algorithms/ScriptAlgorithmExecutorFactory.java
  was constructed…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-94
  - CWE-95
  - CWE-470
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-2026-46562'
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-vmwp-vh32-rj75'
    label: security-advisories@github.com
  - url: 'https://github.com/yamcs/yamcs/security/advisories/GHSA-vmwp-vh32-rj75'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00976
epssPercentile: 0.60524
ingestedAt: '2026-07-20T02:36:03.193Z'
---

## Overview

Yamcs is a mission control framework. Prior to 5.12.7, the Nashorn ScriptEngine used to evaluate user-supplied JavaScript algorithm text in yamcs-core/src/main/java/org/yamcs/algorithms/ScriptAlgorithmExecutorFactory.java was constructed without a ClassFilter, so a user with the ChangeMissionDatabase privilege could override an algorithm through the MdbOverrideApi.updateAlgorithm endpoint and supply JavaScript that reaches arbitrary Java classes (for example Java.type("java.lang.Runtime").getRuntime().exec(...)) to execute arbitrary OS commands as the Yamcs process; in the default configuration with no security.yaml the built-in guest user has superuser=true, making the issue reachable without authentication. 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`