---
id: CVE-2026-106558
title: Backstage is an open framework for building developer portals
summary: >-
  Backstage is an open framework for building developer portals. Prior to
  1.14.8, 1.15.6, and 2.0.1, the @backstage/plugin-techdocs-node package
  improperly validated mapping-style markdown_extensions configuration. An
  authenticated attacke…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: backstage
product: backstage
affected:
  - backstage < 1.50.7
  - 'backstage >= 1.51.0-next.0, < 1.54.9'
  - 'backstage >= 1.55.0-next.0, < 1.55.2'
  - plugin-techdocs-node < 1.14.8
  - 'plugin-techdocs-node >= 1.15.0, < 1.15.6'
  - 'plugin-techdocs-node >= 2.0.0, < 2.0.1'
published: '2026-10-07'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T15:52:18.453'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106558'
references:
  - url: >-
      https://github.com/backstage/backstage/commit/32723a0fe4e12ed80535fc65d5331765c55aa91b
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/commit/944edb51c8524d3664b18f2d57ba101b1c93b709
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/commit/f18e9abcc6051491862b15e4fc60e69f8d52310c
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.50.7'
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.54.9'
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.55.2'
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/security/advisories/GHSA-qmw3-745m-w99g
    label: security-advisories@github.com
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106558'
  - url: 'https://github.com/advisories/GHSA-qmw3-745m-w99g'
tags:
  - nvd
  - cve.org
  - ghsa
  - npm
ingestedAt: '2026-10-07T15:36:04.052Z'
aliases:
  - GHSA-qmw3-745m-w99g
ecosystem: npm
patched:
  - '@backstage/plugin-techdocs-node 1.15.4'
---

## Overview

Backstage is an open framework for building developer portals. Prior to 1.14.8, 1.15.6, and 2.0.1, the @backstage/plugin-techdocs-node package improperly validated mapping-style markdown_extensions configuration. An authenticated attacker who can register or influence an SCM-backed documentation source may bypass TechDocs sanitization and cause Python objects to be imported and instantiated in the generator runtime, leading to arbitrary code execution. Earlier fixes in versions 1.14.6 and 1.15.4 did not fully address the supported mapping representation of markdown_extensions. Impact is greatest when documentation generation runs with backend credentials, filesystem access, or internal network access. This issue is fixed in versions 1.14.8, 1.15.6, and 2.0.1.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-106558)

Affected packages:

- `@backstage/plugin-techdocs-node < 1.15.4`

Patched in:

- `@backstage/plugin-techdocs-node 1.15.4`

Source: https://github.com/advisories/GHSA-qmw3-745m-w99g