RCE in Spaceapplications Yamcs
CVE-2026-46562
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.
Vulnerability class: RCE (Remote Code Execution)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.010 (61.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 61.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000
Affected products
- Spaceapplications Yamcs
- Yamcs — versions < 5.12.7
Weakness classification (CWE)
References
- github.com/yamcs/yamcs/security/advisories/GHSA-vmwp-vh32-rj75 (Exploit, Vendor Advisory)
- github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011 (Patch)
- github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992 (Patch)
- github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7 (Release Notes)
- github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0 (Release Notes)
Frequently asked questions
- What is CVE-2026-46562?
- CVE-2026-46562 is a critical-severity vulnerability in Spaceapplications Yamcs, classified under Code Injection. CVSS score: 9.8/10. Published 2026-07-16.
- How severe is CVE-2026-46562?
- Critical severity. CVSS v3 base score is 9.8 out of 10.