CVE-2026-46621
CWE-94Published: July 16, 2026· Updated: Jul 20, 2026
Official 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.
Risk Analysis
This critical vulnerability in Yamcs allows an authenticated user with ChangeMissionDatabase privilege to achieve remote code execution by overriding Python algorithms. The script evaluation engine's lack of a secure sandbox enables the execution of arbitrary Java classes, leading to compromise of the underlying host operating system. The CVSSv3.1 score of 9.1 highlights the high severity of this flaw.
No public exploit is currently known for this vulnerability. The attack vector is network-based with low attack complexity, indicating it is remotely exploitable.
To mitigate this vulnerability, upgrade Yamcs to version 5.12.7 or 5.13.0 or later. These versions disable algorithm editing by default, preventing the exploitation of this flaw.
Technical Analysis
CVE-2026-46621 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.1.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (6)
Quick Facts
Related CVEs (CWE-94)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-46621 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts