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

{
  "id": "d671e0dea0aa9cfb988ebe41cfd4447f914ccbed7d441cb7443e0766ec392499",
  "url": "https://osv.dev/vulnerability/GHSA-4488-j8vj-vqqv",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Backstage: Remote code execution via crafted markdown_extensions in TechDocs mkdocs.yml",
    "summary": "### 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.",
    "evidence": "osv:GHSA-4488-j8vj-vqqv",
    "products": [
      {
        "name": {
          "value": "@backstage/plugin-techdocs-node",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "1.15.4",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-4488-j8vj-vqqv",
      "aliases": [
        "CVE-2026-106510",
        "GHSA-4488-j8vj-vqqv"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1.15.4"
                }
              ]
            }
          ],
          "package": {
            "name": "@backstage/plugin-techdocs-node",
            "purl": "pkg:npm/%40backstage/plugin-techdocs-node",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-4488-j8vj-vqqv/GHSA-4488-j8vj-vqqv.json"
          }
        }
      ],
      "modified": "2026-10-07T18:15:10.717894363Z",
      "provider": "osv",
      "references": [
        "https://github.com/backstage/backstage/security/advisories/GHSA-4488-j8vj-vqqv",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-106510",
        "https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb",
        "https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d",
        "https://github.com/backstage/backstage",
        "https://github.com/backstage/backstage/releases/tag/v1.50.5",
        "https://github.com/backstage/backstage/releases/tag/v1.54.6"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-183",
          "CWE-470"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": "2026-10-07T15:17:12Z",
        "github_reviewed_at": "2026-10-07T18:03:22Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-106510",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 97143,
  "published_at": "2026-10-07T18:03:22+00:00"
}