Vulnerability · Published Jul 16, 2026 · Assigned by GitHub_M
CVE-2026-46621Yamcs: Authenticated Remote Code Execution (RCE) via Jython Algorithm Code Injection
Critical 9.1
In plain English
A critical-severity code injection in yamcs from yamcs. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 66% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | org.yamcs:yamcs-core | 5.12.7 | GHSA-2g95-6x5q-xjwj |
Affected products (as reported)
Weakness: CWE-94 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
References
- https://github.com/yamcs/yamcs/security/advisories/GHSA-2g95-6x5q-xjwj x_refsource_CONFIRM
- https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011 x_refsource_MISC
- https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992 x_refsource_MISC
- https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7 x_refsource_MISC
- https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0 x_refsource_MISC