Vulnerability-Lookup

GHSA-9JG3-G3WH-W9PJ

Vulnerability from github – Published: 2026-08-28 17:20 – Updated: 2026-08-28 17:20

Summary

Yamcs has Unauthenticated Directory Traversal

Details

Attack type:

Unauthenticated remote 

Impact:

Attackers can access any system files from the underlying host.

Affected components: HttpRequestHandler.java, StaticFileHandler.java

An Unauthenticated Directory Traversal vulnerability exists in Yamcs <=5.8.6, allowing anyone to access any file on the underlying operating system. This allows unauthenticated attackers to download sensitive files and data.

Steps to Reproduce:

Start Yamcs and login as a user
Paste the following URL in the browser and press enter:

http://localhost:8090//etc/passwd

The /etc/passwd file will be downloaded.

Acknowledgements

This vulnerability was discovered by Abderrahim Dahmani while solving a STARPWN 2025 CTF challenge at DEFCON 33 offered by VisionSpace Technologies.

Severity

7.5 (High)


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

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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c 5.11.13"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "org.yamcs:yamcs-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.12.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55552"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-28T17:20:42Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Attack type:\u202f\nUnauthenticated remote\u202f \n\n### Impact: \nAttackers can access any system files from the underlying host.\n\n### Affected components: HttpRequestHandler.java, StaticFileHandler.java\n\nAn Unauthenticated Directory Traversal vulnerability exists in Yamcs \u003c=5.8.6, allowing anyone to access any file on the underlying operating system. This allows unauthenticated attackers to download sensitive files and data.\n\n\u003cimg width=\"2170\" height=\"1289\" alt=\"image\" src=\"https://github.com/user-attachments/assets/8d426da1-5351-4240-a290-8d858be61312\" /\u003e\n\n## Steps to Reproduce:\n1. Start Yamcs and login as a user\n2. Paste the following URL in the browser and press enter:\n\n```\nhttp://localhost:8090//etc/passwd\n```\n\n3. The `/etc/passwd` file will be downloaded.\n\n## Acknowledgements\nThis vulnerability was discovered by Abderrahim Dahmani while solving a STARPWN 2025 CTF challenge at DEFCON 33 offered by VisionSpace Technologies.",
  "id": "GHSA-9jg3-g3wh-w9pj",
  "modified": "2026-08-28T17:20:42Z",
  "published": "2026-08-28T17:20:42Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-9jg3-g3wh-w9pj"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yamcs/yamcs/commit/c7dfd24e469ae1086c23e0fe04401cb1ce4260d4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yamcs/yamcs/commit/f4bc588880c166849e983aa8f65b9c8107d06091"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/yamcs/yamcs"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.11.13"
    },
    {
      "type": "WEB",
      "url": "https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Yamcs has Unauthenticated Directory Traversal"
}

CVE-2026-55552 (GCVE-0-2026-55552)

Vulnerability from cvelistv5 – Published: 2026-08-28 17:18 – Updated: 2026-08-31 18:54

Title

Yamcs: Unauthenticated Directory Traversal

Summary

Yamcs is a mission control framework. Prior to 5.11.13, Yamcs StaticFileHandler.locateFile resolves an unauthenticated request path without using Path.normalize and Path.toAbsolutePath to confirm that the absolute path remains within the configured staticRoots. A path containing traversal segments can escape the intended web root and return an arbitrary readable host file. The flaw is in yamcs-core/src/main/java/org/yamcs/http/StaticFileHandler.java and can disclose sensitive operating-system and application data. This issue is fixed in version 5.11.13, and the 5.12 line is fixed from version 5.12.0.

Severity

7.5 (High)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-31 15:42 UTC

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Assigner

GitHub_M mitre root

References

5 references

URL	Tags
https://github.com/yamcs/yamcs/security/advisorie…	x_refsource_CONFIRM
https://github.com/yamcs/yamcs/commit/c7dfd24e469…	x_refsource_MISC
https://github.com/yamcs/yamcs/commit/f4bc588880c…	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: < 5.12.0

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55552",
                "options": [
                  {
                    "Exploitation": "none"
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                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-31T15:42:22.826410Z",
                "version": "2.0.3"
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        "providerMetadata": {
          "dateUpdated": "2026-08-31T18:54:23.899Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
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    "cna": {
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        {
          "product": "yamcs",
          "vendor": "yamcs",
          "versions": [
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              "status": "affected",
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            }
          ]
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      ],
      "descriptions": [
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        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
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            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
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      "problemTypes": [
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          "descriptions": [
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          "url": "https://github.com/yamcs/yamcs/security/advisories/GHSA-9jg3-g3wh-w9pj"
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    "dateReserved": "2026-06-16T23:01:04.075Z",
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    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
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}

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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