CVE-2026-29184: @backstage/plugin scaffolder backend @backstage/plugin-scaffolder-backend Vulnerable To Potential Session Vulnerability

LOW
Advisory Identifier: GHSA-8qp7-fhr9-fw53
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CVSS 2.0
CWE-532
Published
Advisory Summary

CVE-2026-29184 is a LOW (CVSS 2.0) @backstage/plugin-scaffolder-backend vulnerable to potential session vulnerability (CWE-532: Insertion of Sensitive Information into Log File) affecting @backstage/plugin scaffolder backend libraries in the npm ecosystem. The issue involves @backstage/plugin-scaffolder-backend vulnerable to potential session token exfiltration via log redaction bypass. Remediation is available by upgrading affected packages to version 3.1.4.

CVE-2026-29184 at a Glance

CVE Identifier CVE-2026-29184
GHSA Identifier GHSA-8qp7-fhr9-fw53
Severity LOW
CVSS v3.1 Base Score 2.0
CWE Classification CWE-532: Insertion of Sensitive Information into Log File
Affected Product @backstage/plugin scaffolder backend
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 2.0

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

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

How to Fix CVE-2026-29184

To remediate this vulnerability, upgrade all affected @backstage/plugin scaffolder backend 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 fixed: 3.1.4 
npm install @backstage/plugin-scaffolder-backend@3.1.4
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-scaffolder-backend

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-29184, inspect your project dependencies using npm:

npm ls @backstage/plugin-scaffolder-backend

Analyze the terminal output to locate any version of @backstage/plugin scaffolder backend in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.1.4), your application is affected.

Note: The npm ls @backstage/plugin-scaffolder-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-532: Insertion of Sensitive Information into Log File, where the product writes sensitive information to a log file. In @backstage/plugin scaffolder backend, 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 A malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs. The attack requires: - The ability to register a template in the catalog - A victim who executes the malicious template ### Patches Patched in `@backstage/plugin-scaffolder-backend` version 3.1.4 ### Workarounds - Implement a custom permission policy that restricts scaffolder.task.read so users can only read their own task logs - Restrict who can register templates in the catalog to trusted users only ### Resources - Backstage Scaffolder permissions documentation: https://backstage.io/docs/permissions/plugin-authors/01-setup/ - Backstage Threat Model: https://backstage.io/docs/overview/threat-model/

CVE-2026-29184 Affected @backstage/plugin scaffolder backend Versions

1 component(s)
Fixed Versions:
3.1.4
Product / Package Ecosystem Affected Versions Fixed Version
@backstage/plugin-scaffolder-backend
npm/@backstage/plugin-scaffolder-backend
npm
< 3.1.4
3.1.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/backstage/backstage/security/advisories/GHSA-8qp7-fhr9-fw53
NVD — CVE-2026-29184 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-29184
backstage.io/docs/overview/threa... WEB
https://backstage.io/docs/overview/threat-model
backstage.io/docs/permissions/pl... WEB
https://backstage.io/docs/permissions/plugin-authors/01-setup
@backstage/plugin scaffolder backend Source Repository REPOSITORY
https://github.com/backstage/backstage

Frequently Asked Questions

What is CVE-2026-29184?
CVE-2026-29184 is a security vulnerability in @backstage/plugin scaffolder backend involving @backstage/plugin-scaffolder-backend Vulnerable to Potential Session Token Exfiltration via Log Redaction Bypass under CWE-532: Insertion of Sensitive Information into Log File.
Which @backstage/plugin scaffolder backend versions are affected?
Affected versions include releases prior to 3.1.4 across affected packages: @backstage/plugin-scaffolder-backend.
What version fixes CVE-2026-29184?
Upgrading to 3.1.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @backstage/plugin-scaffolder-backend affected?
Yes, @backstage/plugin-scaffolder-backend is affected in releases prior to 3.1.4. Upgrade your dependency to 3.1.4 or later.
What is the CVSS score of CVE-2026-29184?
CVE-2026-29184 has a CVSS v3.1 base score of 2.0 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-29184?
CVE-2026-29184 is classified under CWE-532: Insertion of Sensitive Information into Log File (The product writes sensitive information to a log file.).
How can I check npm dependencies for CVE-2026-29184?
Run the dependency tree command: 'npm ls @backstage/plugin-scaffolder-backend'. 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-8qp7-fhr9-fw53",
  "modified" : "2026-03-09T15:46:58Z",
  "published" : "2026-03-05T00:23:51Z",
  "aliases" : [ "CVE-2026-29184" ],
  "summary" : "@backstage/plugin-scaffolder-backend Vulnerable to Potential Session Token Exfiltration via Log Redaction Bypass",
  "details" : "### Impact\n\nA malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs.\n\nThe attack requires:\n  - The ability to register a template in the catalog\n  - A victim who executes the malicious template\n\n### Patches\n  Patched in `@backstage/plugin-scaffolder-backend` version 3.1.4\n\n### Workarounds\n  - Implement a custom permission policy that restricts scaffolder.task.read so users can only read their own task logs\n  - Restrict who can register templates in the catalog to trusted users only\n\n### Resources\n  - Backstage Scaffolder permissions documentation: https://backstage.io/docs/permissions/plugin-authors/01-setup/\n  - Backstage Threat Model: https://backstage.io/docs/overview/threat-model/",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@backstage/plugin-scaffolder-backend"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.1.4"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.1.3"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/backstage/backstage/security/advisories/GHSA-8qp7-fhr9-fw53"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-29184"
  }, {
    "type" : "WEB",
    "url" : "https://backstage.io/docs/overview/threat-model"
  }, {
    "type" : "WEB",
    "url" : "https://backstage.io/docs/permissions/plugin-authors/01-setup"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/backstage/backstage"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-532" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-05T00:23:51Z",
    "nvd_published_at" : "2026-03-07T15:15:55Z"
  }
}