Vulnerability-Lookup

GHSA-Q38J-6VCM-2F5M

Vulnerability from github – Published: 2026-10-07 20:25 – Updated: 2026-10-07 20:25

Summary

Backstage: Improper validation of MkDocs plugin configuration in TechDocs

Details

Impact

An authenticated attacker with control over a TechDocs source repository could cause a documentation build to retrieve and publish data from network locations reachable by the build environment. Exposure depends on deployment topology, build mode, and target endpoint protections. Modern cloud metadata services that require tokens or special headers are not directly accessible through the affected behavior.

Patches

Upgrade @backstage/plugin-techdocs-node to a patched version for the applicable release line:

1.14.x: upgrade to 1.14.7 or later in that line, available in Backstage v1.50.6.
1.15.x: upgrade to 1.15.5 or later, available in Backstage v1.54.8.
Current mainline: upgrade to 2.0.0 or later, available in Backstage v1.55.0.

The update removes MkDocs plugins outside the built-in allowlist. To retain additional plugins, review them and configure techdocs.generator.mkdocs.dangerouslyAllowAdditionalPlugins, or supply dangerouslyAllowAdditionalPlugins when creating the generator directly. Plugins supplied through defaultPlugins remain permitted.

Workarounds

Restrict control of TechDocs source repositories and catalog registration to trusted maintainers.
Run documentation builders with outbound access to private and link-local networks denied.
Require token- or header-protected cloud instance metadata services.

Severity

7.7 (High)


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

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JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@backstage/plugin-techdocs-node"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.11.12"
            },
            {
              "fixed": "1.14.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@backstage/plugin-techdocs-node"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.15.0"
            },
            {
              "fixed": "1.15.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-106455"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-07T20:25:19Z",
    "nvd_published_at": "2026-10-06T21:17:15Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nAn authenticated attacker with control over a TechDocs source repository could cause a documentation build to retrieve and publish data from network locations reachable by the build environment. Exposure depends on deployment topology, build mode, and target endpoint protections. Modern cloud metadata services that require tokens or special headers are not directly accessible through the affected behavior.\n\n### Patches\n\nUpgrade `@backstage/plugin-techdocs-node` to a patched version for the applicable release line:\n\n- `1.14.x`: upgrade to `1.14.7` or later in that line, available in [Backstage v1.50.6](https://github.com/backstage/backstage/releases/tag/v1.50.6).\n- `1.15.x`: upgrade to `1.15.5` or later, available in [Backstage v1.54.8](https://github.com/backstage/backstage/releases/tag/v1.54.8).\n- Current mainline: upgrade to `2.0.0` or later, available in [Backstage v1.55.0](https://github.com/backstage/backstage/releases/tag/v1.55.0).\n\nThe update removes MkDocs plugins outside the built-in allowlist. To retain additional plugins, review them and configure `techdocs.generator.mkdocs.dangerouslyAllowAdditionalPlugins`, or supply `dangerouslyAllowAdditionalPlugins` when creating the generator directly. Plugins supplied through `defaultPlugins` remain permitted.\n\n### Workarounds\n\n- Restrict control of TechDocs source repositories and catalog registration to trusted maintainers.\n- Run documentation builders with outbound access to private and link-local networks denied.\n- Require token- or header-protected cloud instance metadata services.",
  "id": "GHSA-q38j-6vcm-2f5m",
  "modified": "2026-10-07T20:25:19Z",
  "published": "2026-10-07T20:25:19Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/security/advisories/GHSA-q38j-6vcm-2f5m"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-106455"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/commit/28aa82ae2815988721dd7bbf43cd69c431dcd71b"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/commit/9f76ea445088961f68c364764cc4b7734f368fc0"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/backstage/backstage"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/releases/tag/v1.50.6"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/releases/tag/v1.54.8"
    },
    {
      "type": "WEB",
      "url": "https://github.com/backstage/backstage/releases/tag/v1.55.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Backstage: Improper validation of MkDocs plugin configuration in TechDocs"
}

CVE-2026-106455 (GCVE-0-2026-106455)

Vulnerability from cvelistv5 – Published: 2026-10-06 20:06 – Updated: 2026-10-06 20:06

Title

Backstage: Improper validation of MkDocs plugin configuration in TechDocs

Summary

Backstage is an open framework for building developer portals. From 0.11.12 until 1.14.7 and 1.15.5, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs plugin configuration in techdocs. An authenticated attacker with control over a TechDocs source repository could cause a documentation build to retrieve and publish data from network locations reachable by the build environment. Exposure depends on deployment topology, build mode, and target endpoint protections. Modern cloud metadata services that require tokens or special headers are not directly accessible through the affected behavior. This issue is fixed in @backstage/plugin-techdocs-node versions 1.14.7 and 1.15.5.

Severity

7.7 (High)


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

CWE

CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M mitre root Scorecard

References

6 references

URL	Tags
https://github.com/backstage/backstage/security/a…	x_refsource_CONFIRM
https://github.com/backstage/backstage/commit/28a…	x_refsource_MISC
https://github.com/backstage/backstage/commit/9f7…	x_refsource_MISC
https://github.com/backstage/backstage/releases/t…	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: >= 0.71.1, < 1.50.6 Affected: >= 1.51.0-next.0, < 1.54.8
@backstage	plugin-techdocs-node	Affected: >= 0.11.12, < 1.14.7 Affected: >= 1.15.0, < 1.15.5

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "backstage",
          "vendor": "backstage",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.71.1, \u003c 1.50.6"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.51.0-next.0, \u003c 1.54.8"
            }
          ]
        },
        {
          "product": "plugin-techdocs-node",
          "vendor": "@backstage",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.11.12, \u003c 1.14.7"
            },
            {
              "status": "affected",
              "version": "\u003e= 1.15.0, \u003c 1.15.5"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Backstage is an open framework for building developer portals. From 0.11.12 until 1.14.7 and 1.15.5, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs plugin configuration in techdocs. An authenticated attacker with control over a TechDocs source repository could cause a documentation build to retrieve and publish data from network locations reachable by the build environment. Exposure depends on deployment topology, build mode, and target endpoint protections. Modern cloud metadata services that require tokens or special headers are not directly accessible through the affected behavior. This issue is fixed in @backstage/plugin-techdocs-node versions 1.14.7 and 1.15.5."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-06T20:06:06.505Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/backstage/backstage/security/advisories/GHSA-q38j-6vcm-2f5m",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/backstage/backstage/security/advisories/GHSA-q38j-6vcm-2f5m"
        },
        {
          "name": "https://github.com/backstage/backstage/commit/28aa82ae2815988721dd7bbf43cd69c431dcd71b",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/commit/28aa82ae2815988721dd7bbf43cd69c431dcd71b"
        },
        {
          "name": "https://github.com/backstage/backstage/commit/9f76ea445088961f68c364764cc4b7734f368fc0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/commit/9f76ea445088961f68c364764cc4b7734f368fc0"
        },
        {
          "name": "https://github.com/backstage/backstage/releases/tag/v1.50.6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/releases/tag/v1.50.6"
        },
        {
          "name": "https://github.com/backstage/backstage/releases/tag/v1.54.8",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/releases/tag/v1.54.8"
        },
        {
          "name": "https://github.com/backstage/backstage/releases/tag/v1.55.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/backstage/backstage/releases/tag/v1.55.0"
        }
      ],
      "source": {
        "advisory": "GHSA-q38j-6vcm-2f5m",
        "discovery": "UNKNOWN"
      },
      "title": "Backstage: Improper validation of MkDocs plugin configuration in TechDocs"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-106455",
    "datePublished": "2026-10-06T20:06:06.505Z",
    "dateReserved": "2026-10-06T16:49:40.591Z",
    "dateUpdated": "2026-10-06T20:06:06.505Z",
    "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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