Backstage: Potential file exposure through local TechDocs publisher

Backstage is an open framework for building developer portals. Prior to 1.15.4, the @backstage/plugin-techdocs-node package is affected by potential file exposure through local techdocs publisher. When using the local TechDocs publisher (techdocs.publisher.type: 'local'), it was possible for the documentation serving endpoint to follow filesystem references outside the intended documentation tree, potentially exposing host files to authenticated users. This is mitigated by the fact that exploration requires preconditions that do not arise through normal MkDocs operation. Cloud-based publishers (S3, GCS, Azure Blob Storage) are not affected. This issue is fixed in version 1.15.4.

Problem type

Affected products

backstage

backstage

< 1.54.6 - AFFECTED

@backstage

plugin-techdocs-node

< 1.15.4 - AFFECTED

References

https://github.com/backstage/backstage/security/advisories/GHSA-cm77-ch27-6w6v

https://github.com/backstage/backstage/security/advisories/GHSA-cm77-ch27-6w6v

x_refsource_CONFIRM

https://github.com/backstage/backstage/commit/6aecb26f337ffec1d4e67ce903cf1e39b6082ec4

https://github.com/backstage/backstage/commit/6aecb26f337ffec1d4e67ce903cf1e39b6082ec4

x_refsource_MISC

https://github.com/backstage/backstage/releases/tag/v1.54.6

https://github.com/backstage/backstage/releases/tag/v1.54.6

x_refsource_MISC

JSON source

https://cveawg.mitre.org/api/cve/CVE-2026-106508

Click to expand

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-106508",
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "dateUpdated": "2026-10-06T21:47:35.516Z",
    "dateReserved": "2026-10-06T18:46:47.767Z",
    "datePublished": "2026-10-06T21:47:35.516Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M",
        "dateUpdated": "2026-10-06T21:47:35.516Z"
      },
      "title": "Backstage: Potential file exposure through local TechDocs publisher",
      "descriptions": [
        {
          "lang": "en",
          "value": "Backstage is an open framework for building developer portals. Prior to 1.15.4, the @backstage/plugin-techdocs-node package is affected by potential file exposure through local techdocs publisher. When using the local TechDocs publisher (techdocs.publisher.type: 'local'), it was possible for the documentation serving endpoint to follow filesystem references outside the intended documentation tree, potentially exposing host files to authenticated users. This is mitigated by the fact that exploration requires preconditions that do not arise through normal MkDocs operation. Cloud-based publishers (S3, GCS, Azure Blob Storage) are not affected. This issue is fixed in version 1.15.4."
        }
      ],
      "affected": [
        {
          "vendor": "backstage",
          "product": "backstage",
          "versions": [
            {
              "version": "< 1.54.6",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "@backstage",
          "product": "plugin-techdocs-node",
          "versions": [
            {
              "version": "< 1.15.4",
              "status": "affected"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')",
              "cweId": "CWE-22",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-59: Improper Link Resolution Before File Access ('Link Following')",
              "cweId": "CWE-59",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://github.com/backstage/backstage/security/advisories/GHSA-cm77-ch27-6w6v",
          "name": "https://github.com/backstage/backstage/security/advisories/GHSA-cm77-ch27-6w6v",
          "tags": [
            "x_refsource_CONFIRM"
          ]
        },
        {
          "url": "https://github.com/backstage/backstage/commit/6aecb26f337ffec1d4e67ce903cf1e39b6082ec4",
          "name": "https://github.com/backstage/backstage/commit/6aecb26f337ffec1d4e67ce903cf1e39b6082ec4",
          "tags": [
            "x_refsource_MISC"
          ]
        },
        {
          "url": "https://github.com/backstage/backstage/releases/tag/v1.54.6",
          "name": "https://github.com/backstage/backstage/releases/tag/v1.54.6",
          "tags": [
            "x_refsource_MISC"
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
            "attackVector": "NETWORK",
            "attackComplexity": "HIGH",
            "privilegesRequired": "LOW",
            "userInteraction": "NONE",
            "scope": "UNCHANGED",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM"
          }
        }
      ]
    }
  }
}