Vulnerability-Lookup

GHSA-4488-J8VJ-VQQV

Vulnerability from github – Published: 2026-10-07 18:03 – Updated: 2026-10-07 18:03

Summary

Backstage: Remote code execution via crafted markdown_extensions in TechDocs mkdocs.yml

Details

Impact

An authenticated user who can register catalog entities can provide a crafted mkdocs.yml causing arbitrary OS command execution on the TechDocs build host when the docs are built.

Patches

Patched in @backstage/plugin-techdocs-node, version 1.15.4.

Workarounds

If you cannot upgrade immediately:

Switch to techdocs.builder: external to isolate TechDocs builds in a container.
Restrict who can register catalog entities with TechDocs annotations.
Audit existing catalog entities for suspicious markdown_extensions values in their mkdocs.yml files.

Severity

7.7 (High)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@backstage/plugin-techdocs-node"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.15.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-106510"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-183",
      "CWE-470"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-07T18:03:22Z",
    "nvd_published_at": "2026-10-07T15:17:12Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nAn authenticated user who can register catalog entities can provide a crafted `mkdocs.yml` causing arbitrary OS command execution on the TechDocs build host when the docs are built.\n\n### Patches\n\nPatched in `@backstage/plugin-techdocs-node`, version `1.15.4`.\n\n### Workarounds\n\nIf you cannot upgrade immediately:\n\n- Switch to `techdocs.builder: external` to isolate TechDocs builds in a container.\n- Restrict who can register catalog entities with TechDocs annotations.\n- Audit existing catalog entities for suspicious `markdown_extensions` values in their `mkdocs.yml` files.",
  "id": "GHSA-4488-j8vj-vqqv",
  "modified": "2026-10-07T18:03:22Z",
  "published": "2026-10-07T18:03:22Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/security/advisories/GHSA-4488-j8vj-vqqv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-106510"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/backstage/backstage"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/releases/tag/v1.50.5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/releases/tag/v1.54.6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Backstage: Remote code execution via crafted markdown_extensions in TechDocs mkdocs.yml"
}

CVE-2026-106510 (GCVE-0-2026-106510)

Vulnerability from cvelistv5 – Published: 2026-10-07 14:36 – Updated: 2026-10-07 17:15

Title

Backstage: Remote code execution via crafted markdown_extensions in TechDocs mkdocs.yml

Summary

Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by remote code execution via crafted markdown_extensions in techdocs mkdocs.yml. An authenticated user who can register catalog entities can provide a crafted mkdocs.yml causing arbitrary OS command execution on the TechDocs build host when the docs are built. This issue is fixed in versions 1.14.6 and 1.15.4.

Severity

7.7 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-07 17:13 UTC

CWE

CWE-183 - Permissive List of Allowed Inputs
CWE-470 - Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')

Assigner

GitHub_M mitre root Scorecard

References

5 references

URL	Tags
https://github.com/backstage/backstage/security/a…	x_refsource_CONFIRM
https://github.com/backstage/backstage/commit/02c…	x_refsource_MISC
https://github.com/backstage/backstage/commit/a90…	x_refsource_MISC
https://github.com/backstage/backstage/releases/t…	x_refsource_MISC
https://github.com/backstage/backstage/releases/t…	x_refsource_MISC

Impacted products

2 products

Vendor	Product	Version
backstage	backstage	Affected: < 1.50.5 Affected: >= 1.51.0-next.0, < 1.54.6
@backstage	plugin-techdocs-node	Affected: < 1.14.6 Affected: >= 1.15.0, < 1.15.4

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-106510",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-07T17:13:13.346488Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-07T17:15:43.410Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "backstage",
          "vendor": "backstage",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.50.5"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.51.0-next.0, \u003c 1.54.6"
            }
          ]
        },
        {
          "product": "plugin-techdocs-node",
          "vendor": "@backstage",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.14.6"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.15.0, \u003c 1.15.4"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by remote code execution via crafted markdown_extensions in techdocs mkdocs.yml. An authenticated user who can register catalog entities can provide a crafted mkdocs.yml causing arbitrary OS command execution on the TechDocs build host when the docs are built. This issue is fixed in versions 1.14.6 and 1.15.4."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 7.7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
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          "descriptions": [
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              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
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              "cweId": "CWE-470",
              "description": "CWE-470: Use of Externally-Controlled Input to Select Classes or Code (\u0027Unsafe Reflection\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-07T14:36:53.929Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/backstage/backstage/security/advisories/GHSA-4488-j8vj-vqqv",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/backstage/backstage/security/advisories/GHSA-4488-j8vj-vqqv"
        },
        {
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          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb"
        },
        {
          "name": "https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d"
        },
        {
          "name": "https://github.com/backstage/backstage/releases/tag/v1.50.5",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/releases/tag/v1.50.5"
        },
        {
          "name": "https://github.com/backstage/backstage/releases/tag/v1.54.6",
          "tags": [
            "x_refsource_MISC"
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          "url": "https://github.com/backstage/backstage/releases/tag/v1.54.6"
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      ],
      "source": {
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        "discovery": "UNKNOWN"
      },
      "title": "Backstage: Remote code execution via crafted markdown_extensions in TechDocs mkdocs.yml"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
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    "datePublished": "2026-10-07T14:36:53.929Z",
    "dateReserved": "2026-10-06T18:46:47.767Z",
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    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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