---
title: "CVE-2026-46562: Yamcs Vulnerable to Remote Code Execution via Mission Database algorithm override"
url: https://erroneo.us/security/cve/CVE-2026-46562/
description: "CVE-2026-46562 (org.yamcs:yamcs-core (Maven)): Yamcs is a mission control framework. Prior to 5.12.7, the Nashorn ScriptEngine used to evaluate…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-07-16
date_modified: 2026-07-16
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-46562"
kev: false
cvss: 9.8
epss: 0.00976
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-46562: Yamcs Vulnerable to Remote Code Execution via Mission Database algorithm override

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 1.0% , percentile 62: FIRST’s model estimates a 1.0% chance of exploitation activity in the next 30 days, higher than 62% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes org.yamcs:yamcs-core (Maven) < 5.12.7, fixed in 5.12.7 . Check your lockfile, including transitive dependencies.

## What it is

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 packages

- Maven `org.yamcs:yamcs-core` < 5.12.7 → fixed: 5.12.7

## Affected products (CVE record)

- yamcs yamcs: < 5.12.7

## Severity

- GitHub_M CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.8 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.98% probability of exploitation activity in the next 30 days; percentile 62.

## Sources

- [GitHub Advisory GHSA-vmwp-vh32-rj75](https://github.com/advisories/GHSA-vmwp-vh32-rj75)
- [CVE.org record CVE-2026-46562](https://www.cve.org/CVERecord?id=CVE-2026-46562)
- [NVD entry CVE-2026-46562](https://nvd.nist.gov/vuln/detail/CVE-2026-46562)
- [github.com](https://github.com/yamcs/yamcs/security/advisories/GHSA-vmwp-vh32-rj75)
- [github.com](https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011)
- [github.com](https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992)
- [github.com](https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7)
- [github.com](https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0)

---
Source page: https://erroneo.us/security/cve/CVE-2026-46562/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt