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TI-2026-34277 Aliases CVE-2026-46621GHSA-2g95-6x5q-xjwj

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

Priority HIGH 74CWE-94Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-94.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01116 66th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed yamcs (yamcs): 5.12.7org.yamcs:yamcs-core (Maven): 5.12.7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
yamcsyamcsbefore 5.12.75.12.7Patch availableCNA
—org.yamcs:yamcs-core (Maven)before 5.12.75.12.7Patch availableGHSA-2g95-6x5q-xjwj
  • yamcs Vendoryamcs Affected before 5.12.7 Fixed in 5.12.7 Patch available CNA
  • org.yamcs:yamcs-core (Maven) Vendor— Affected before 5.12.7 Fixed in 5.12.7 Patch available GHSA-2g95-6x5q-xjwj

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:spaceapplications:yamcs:*:*:*:*:*:*:*:*before 5.12.7Vulnerableyamcs
  • cpe:2.3:a:spaceapplications:yamcs:*:*:*:*:*:*:*:* Versions before 5.12.7 Vulnerable ·yamcs

Remediation

  • Fix · CNA yamcs (yamcs) Fixed in 5.12.7
  • Fix · GHSA-2g95-6x5q-xjwj org.yamcs:yamcs-core (Maven) Fixed in 5.12.7 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-46621
  2. 2026-10-03 Alias added: GHSA-2g95-6x5q-xjwj

References

Exploit 1

Patch 2

Other 3

  • TI-2026-34240 Yamcs: Remote Code Execution via Mission Database algorithm override CVSS 3.1CRITICAL 9.8
  • TI-2026-32507 Yamcs: No Rate Limiting on Authentication Endpoint CVSS 3.1CRITICAL 9.8
  • TI-2026-32532 Yamcs: Server-Side Code Injection (RCE) via Janino Expression Engine in `JavaExprAlgorithmExecutionFactory` CVSS 3.1CRITICAL 9.1
  • TI-2026-40093 Yamcs: Insecure Direct Object Reference (IDOR) in PacketsApi allows unprivileged users to dump all telemetry packets CVSS 3.1MEDIUM 4.3
  • TI-2026-32506 Yamcs: Unauthorized user enumeration via IAM API endpoints CVSS 3.1MEDIUM 4.3
  • TI-2023-24268 Directory Traversal vulnerability in the storage functionality of the API in Yamcs 5.8.6… CVSS 3.1CRITICAL 9.1
See all 10 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences