CVE-2026-106560: Backstage Improper Repository Path Validation Vulnerability

HIGH
Advisory Identifier: GHSA-2cmg-v53w-8xfp
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CVSS 7.1
CWE-22
Published
Advisory Summary

CVE-2026-106560 is a HIGH (CVSS 7.1) improper repository path validation vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Backstage libraries in the npm ecosystem. The issue involves improper repository path validation in a scaffolder backend module. Remediation is available by upgrading affected packages to version 0.3.25.

CVE-2026-106560 at a Glance

CVE Identifier CVE-2026-106560
GHSA Identifier GHSA-2cmg-v53w-8xfp
Severity HIGH
CVSS v3.1 Base Score 7.1
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Backstage
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.1

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

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

How to Fix CVE-2026-106560

To remediate this vulnerability, upgrade all affected Backstage 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-scaffolder-backend-module-confluence-to-markdown fixed: 0.3.25 
npm install @backstage/plugin-scaffolder-backend-module-confluence-to-markdown@0.3.25
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-scaffolder-backend-module-confluence-to-markdown

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-106560, inspect your project dependencies using npm:

npm ls @backstage/plugin-scaffolder-backend-module-confluence-to-markdown

Analyze the terminal output to locate any version of Backstage in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.25), your application is affected.

Note: The npm ls @backstage/plugin-scaffolder-backend-module-confluence-to-markdown 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-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Backstage, 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 An authenticated user who can execute an affected template and control its repository file location may cause generated content to be written outside the task workspace, within locations writable by the Backstage backend process. ### Patches Patched in `@backstage/plugin-scaffolder-backend-module-confluence-to-markdown` version `0.3.25` ### Workarounds - Restrict execution of templates using the affected action to trusted users. - Remove or disable the affected action until the patched package is deployed.

CVE-2026-106560 Affected Backstage Versions

1 component(s)
Fixed Versions:
0.3.25
Product / Package Ecosystem Affected Versions Fixed Version
@backstage/plugin-scaffolder-backend-module-confluence-to-markdown
npm/@backstage/plugin-scaffolder-backend-module-confluence-to-markdown
npm
< 0.3.25
0.3.25

References

GitHub Advisory / Wiki ADVISORY
https://github.com/backstage/backstage/security/advisories/GHSA-2cmg-v53w-8xfp
NVD — CVE-2026-106560 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-106560
Security Fix Commit FIX COMMIT
https://github.com/backstage/backstage/commit/5f0000c1d0af05571e357926b3fa33a453337ff0
Backstage Source Repository REPOSITORY
https://github.com/backstage/backstage
Backstage Release RELEASE
https://github.com/backstage/backstage/releases/tag/v1.54.6

Frequently Asked Questions

What is CVE-2026-106560?
CVE-2026-106560 is a security vulnerability in Backstage involving Improper repository path validation in a Scaffolder backend module under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Backstage versions are affected?
Affected versions include releases prior to 0.3.25 across affected packages: @backstage/plugin-scaffolder-backend-module-confluence-to-markdown.
What version fixes CVE-2026-106560?
Upgrading to 0.3.25 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @backstage/plugin-scaffolder-backend-module-confluence-to-markdown affected?
Yes, @backstage/plugin-scaffolder-backend-module-confluence-to-markdown is affected in releases prior to 0.3.25. Upgrade your dependency to 0.3.25 or later.
What is the CVSS score of CVE-2026-106560?
CVE-2026-106560 has a CVSS v3.1 base score of 7.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L.
What CWE is associated with CVE-2026-106560?
CVE-2026-106560 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check npm dependencies for CVE-2026-106560?
Run the dependency tree command: 'npm ls @backstage/plugin-scaffolder-backend-module-confluence-to-markdown'. 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-2cmg-v53w-8xfp",
  "modified" : "2026-10-07T18:02:59Z",
  "published" : "2026-10-07T18:02:59Z",
  "aliases" : [ "CVE-2026-106560" ],
  "summary" : "Backstage: Improper repository path validation in a Scaffolder backend module",
  "details" : "### Impact\n\nAn authenticated user who can execute an affected template and control its repository file location may cause generated content to be written outside the task workspace, within locations writable by the Backstage backend process.\n\n### Patches\n\nPatched in `@backstage/plugin-scaffolder-backend-module-confluence-to-markdown` version `0.3.25`\n\n### Workarounds\n\n- Restrict execution of templates using the affected action to trusted users.\n- Remove or disable the affected action until the patched package is deployed.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@backstage/plugin-scaffolder-backend-module-confluence-to-markdown"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.25"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/backstage/backstage/security/advisories/GHSA-2cmg-v53w-8xfp"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-106560"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/backstage/backstage/commit/5f0000c1d0af05571e357926b3fa33a453337ff0"
  }, {
    "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" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-07T18:02:59Z",
    "nvd_published_at" : "2026-10-07T15:17:17Z"
  }
}