Vulnerabilities in pkg:npm/@backstage/plugin-techdocs-backend
PACKAGECVE-2026-106489 is a MODERATE (CVSS 6.5) remote code execution vulnerability (CWE-862: Missing Authorization) affecting Backstage libraries in the npm ecosystem. The issue involves improper authorization enforcement for techdocs static content. Remediation is available by upgrading affected packages to version 2.2.4.
pkg:npm/@backstage/plugin-techdocs-backend
Vulnerability advisories affecting package pkg:npm/@backstage/plugin-techdocs-backend. Select an advisory below to view technical details or fixes.
| Advisory ID | CVE / NVD | Severity | Summary |
|---|---|---|---|
| GHSA-rg9r-hr7g-5gc2 | CVE-2026-106489 | MODERATE | Backstage: Improper authorization enforcement for TechDocs static content |
| GHSA-7mfx-xg57-53c9 | CVE-2026-106490 | MODERATE | Backstage: Improper input validation in TechDocs static content requests |
| GHSA-39v3-f278-vj3g | CVE-2024-45816 | HIGH | @backstage/plugin-techdocs-backend storage bucket Directory Traversal vulnerability |
| GHSA-5j94-f3mf-8685 | CVE-2024-46976 | MODERATE | @backstage/plugin-techdocs-backend vulnerable to circumvention of cross site scripting protection |
CVE-2026-106489 at a Glance
Security Impact
CVSS: 6.5
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:H/I:N/A:N).
How to Fix CVE-2026-106489
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.
npm install @backstage/plugin-techdocs-backend@2.2.4Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls @backstage/plugin-techdocs-backendHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2026-106489, inspect your project dependencies using npm:
npm ls @backstage/plugin-techdocs-backendAnalyze 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 2.2.4), your application is affected.
Note: The npm ls @backstage/plugin-techdocs-backend 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-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. 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
CVE-2026-106489 Affected Backstage Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
@backstage/plugin-techdocs-backend
|
npm |
< 2.2.4
|
2.2.4
|
References
Frequently Asked Questions
What is CVE-2026-106489?
Which Backstage versions are affected?
What version fixes CVE-2026-106489?
Is @backstage/plugin-techdocs-backend affected?
What is the CVSS score of CVE-2026-106489?
What CWE is associated with CVE-2026-106489?
How can I check npm dependencies for CVE-2026-106489?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-rg9r-hr7g-5gc2",
"modified" : "2026-10-07T18:00:06Z",
"published" : "2026-10-07T18:00:06Z",
"aliases" : [ "CVE-2026-106489" ],
"summary" : "Backstage: Improper authorization enforcement for TechDocs static content",
"details" : "### Impact\n\nAn authenticated user with access to one TechDocs documentation site could craft a URL able to read documentation belonging to a different entity. This only affects deployments using the external TechDocs builder with an external storage provider (S3, GCS, etc.) and the permission framework enabled. Instances that do not use the permission framework are unaffected, since TechDocs content is visible to all authenticated users by design.\n\n### Patches\n\nPatched in `@backstage/plugin-techdocs-backend` version `2.2.4`\n\n### Workarounds\n\n- None other than upgrading. Deployments that serve TechDocs from local storage are not affected.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "@backstage/plugin-techdocs-backend"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "2.2.4"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/backstage/backstage/security/advisories/GHSA-rg9r-hr7g-5gc2"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-106489"
}, {
"type" : "WEB",
"url" : "https://github.com/backstage/backstage/commit/bf6bbf7326ada7d96d7b2c4ebc4a71546106f311"
}, {
"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-862" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-10-07T18:00:06Z",
"nvd_published_at" : "2026-10-06T21:17:17Z"
}
}