{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "1.50.5"
              },
              {
                "introduced": "1.51.0-next.0"
              },
              {
                "fixed": "1.54.6"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "f3e982bd0530f51760c8a70d21eafaa7aed2e6eb"
            },
            {
              "introduced": "e2fdc2b61fe9046574a8fc1d99b18053018db0a8"
            },
            {
              "fixed": "0e67bc1fc88fba3a8cb716d3584cef05ecbcf9a8"
            }
          ],
          "repo": "https://github.com/backstage/backstage",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-f7v3-xhm6-w245"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-22",
      "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/106xxx/CVE-2026-106557.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "fixed": "1.14.6"
          },
          {
            "introduced": "1.15.0"
          },
          {
            "fixed": "1.15.4"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package did not sufficiently validate TechDocs Markdown extension configuration. An authenticated user who can register or modify documentation sources may cause a TechDocs build to access resources outside the intended documentation boundary, potentially exposing backend-host data or internal network resources. This issue is fixed in versions 1.14.6 and 1.15.4 when pymdown-extensions 10.21.3 or later is also used, normally through mkdocs-techdocs-core 1.7.0 or later.",
  "id": "CVE-2026-106557",
  "modified": "2026-10-08T02:31:10.065292831Z",
  "published": "2026-10-07T16:22:53.320Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/106xxx/CVE-2026-106557.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/backstage/backstage/commit/017ace52d9b327ededc6704cf17799c875ae0f29"
    },
    {
      "type": "FIX",
      "url": "https://github.com/backstage/backstage/commit/2d9de4ca117a529de4b6ed7dfb7aa507ca7b3f91"
    },
    {
      "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"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/backstage/backstage/security/advisories/GHSA-f7v3-xhm6-w245"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-106557"
    }
  ],
  "schema_version": "1.9.0",
  "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 input validation in TechDocs Markdown extension configuration"
}