CVE-2026-106508: @backstage/plugin techdocs node Backstage Has Potential File Exposure Vulnerability

MODERATE
Advisory Identifier: GHSA-cm77-ch27-6w6v
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CVSS 5.3
CWE-59 CWE-22
Published
Advisory Summary

CVE-2026-106508 is a MODERATE (CVSS 5.3) backstage has potential file exposure vulnerability (CWE-59: Improper Link Resolution Before File Access ('Link Following')) affecting @backstage/plugin techdocs node libraries in the npm ecosystem. The issue involves backstage has potential file exposure through local techdocs publisher. Remediation is available by upgrading affected packages to version 1.15.4.

CVE-2026-106508 at a Glance

CVE Identifier CVE-2026-106508
GHSA Identifier GHSA-cm77-ch27-6w6v
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-59: Improper Link Resolution Before File Access ('Link Following')
Affected Product @backstage/plugin techdocs node
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-106508

To remediate this vulnerability, upgrade all affected @backstage/plugin techdocs node dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@backstage/plugin-techdocs-node fixed: 1.15.4 
npm install @backstage/plugin-techdocs-node@1.15.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls @backstage/plugin-techdocs-node

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-106508, inspect your project dependencies using npm:

npm ls @backstage/plugin-techdocs-node

Analyze the terminal output to locate any version of @backstage/plugin techdocs node in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.15.4), your application is affected.

Note: The npm ls @backstage/plugin-techdocs-node command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following'), where the product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource. In @backstage/plugin techdocs node, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact 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. ### Patches Patched in `@backstage/plugin-techdocs-node` version `1.15.4` ### Workarounds If you cannot upgrade immediately, consider switching to an external store for published TechDocs content (e.g. `awsS3`, `googleGcs`, or `azureBlobStorage` publishers)

CVE-2026-106508 Affected @backstage/plugin techdocs node Versions

1 component(s)
Fixed Versions:
1.15.4
Product / Package Ecosystem Affected Versions Fixed Version
@backstage/plugin-techdocs-node
npm/@backstage/plugin-techdocs-node
npm
< 1.15.4
1.15.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/backstage/backstage/security/advisories/GHSA-cm77-ch27-6w6v
NVD — CVE-2026-106508 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-106508
Security Fix Commit FIX COMMIT
https://github.com/backstage/backstage/commit/6aecb26f337ffec1d4e67ce903cf1e39b6082ec4
@backstage/plugin techdocs node Source Repository REPOSITORY
https://github.com/backstage/backstage
@backstage/plugin techdocs node Release RELEASE
https://github.com/backstage/backstage/releases/tag/v1.54.6

Frequently Asked Questions

What is CVE-2026-106508?
CVE-2026-106508 is a security vulnerability in @backstage/plugin techdocs node involving Backstage has potential file exposure through local TechDocs publisher under CWE-59: Improper Link Resolution Before File Access ('Link Following').
Which @backstage/plugin techdocs node versions are affected?
Affected versions include releases prior to 1.15.4 across affected packages: @backstage/plugin-techdocs-node.
What version fixes CVE-2026-106508?
Upgrading to 1.15.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @backstage/plugin-techdocs-node affected?
Yes, @backstage/plugin-techdocs-node is affected in releases prior to 1.15.4. Upgrade your dependency to 1.15.4 or later.
What is the CVSS score of CVE-2026-106508?
CVE-2026-106508 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-106508?
CVE-2026-106508 is classified under CWE-59: Improper Link Resolution Before File Access ('Link Following') (The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.).
How can I check npm dependencies for CVE-2026-106508?
Run the dependency tree command: 'npm ls @backstage/plugin-techdocs-node'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cm77-ch27-6w6v",
  "modified" : "2026-10-07T16:23:46Z",
  "published" : "2026-10-07T16:23:46Z",
  "aliases" : [ "CVE-2026-106508" ],
  "summary" : "Backstage has potential file exposure through local TechDocs publisher",
  "details" : "### Impact\n\nWhen 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.\n\nThis 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.\n\n### Patches\n\nPatched in `@backstage/plugin-techdocs-node` version `1.15.4`\n\n### Workarounds\n\nIf you cannot upgrade immediately, consider switching to an external store for published TechDocs content (e.g. `awsS3`, `googleGcs`, or `azureBlobStorage` publishers)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@backstage/plugin-techdocs-node"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.15.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/backstage/backstage/security/advisories/GHSA-cm77-ch27-6w6v"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-106508"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/backstage/backstage/commit/6aecb26f337ffec1d4e67ce903cf1e39b6082ec4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/backstage/backstage"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/backstage/backstage/releases/tag/v1.54.6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22", "CWE-59" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-07T16:23:46Z",
    "nvd_published_at" : "2026-10-06T22:17:06Z"
  }
}