CVE-2026-46621 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-46621CRITICAL

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

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   H   N  C  H  H  H    9.1   .0100   60.0     —

AFFECTED
  Product  Versions    Fixed
  yamcs    < 5.12.7 –  —

TIMELINE
  May 15  Reserved by GitHub_M
  Jul 16  EXPLOIT PUBLISHED — CVE-2026-46621 (yamcs). Public exploit reference added.
  Jul 16  Published (CNA: GitHub_M)

CWE-94 · CNA: GitHub_M · CVSS v3.1 · 5 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
May 15, 2026	Reserved	Reserved by GitHub_M
July 16, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-46621 (yamcs). Public exploit reference added.
July 16, 2026	Published	Published (CNA: GitHub_M)

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
yamcs	yamcs	—	< 5.12.7	—

Weaknesses

CWE-94

References (5)

https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011 [Patch]
https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992 [Patch]
https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7 [Release Notes]
https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0 [Release Notes]
https://github.com/yamcs/yamcs/security/advisories/GHSA-2g95-6x5q-xjwj [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-46621 at cve.org

Vendors: yamcs

Weaknesses: CWE-94

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-46621 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.