---
id: CVE-2026-88064
title: Backstage is an open framework for building developer portals
summary: >-
  Backstage is an open framework for building developer portals. Prior to 1.14.6
  and from 1.15.0 until 1.15.4, the @backstage/plugin-techdocs-node package
  insufficiently validates mkdocs.yml supplied by an authenticated user who can
  regist…
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-20
  - CWE-1336
vendor: backstage
product: backstage
affected:
  - backstage < 1.14.6
  - 'backstage >= 1.15.0, < 1.15.4'
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T16:17:19.897'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88064'
references:
  - url: >-
      https://github.com/backstage/backstage/commit/017ace52d9b327ededc6704cf17799c875ae0f29
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/commit/25125ee727a3de3418a8fa6a9e458cd5b73ecf26
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/commit/a7d995f11a5d27f0efbdbe8bb6c21b06988c79c9
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.50.5'
    label: security-advisories@github.com
  - url: 'https://github.com/backstage/backstage/releases/tag/v1.54.6'
    label: security-advisories@github.com
  - url: >-
      https://github.com/backstage/backstage/security/advisories/GHSA-292q-8mf5-h6g3
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-16T15:46:28.697895Z'
ingestedAt: '2026-09-16T14:57:28.062Z'
epss: 0.00875
epssPercentile: 0.57256
---

## Overview

Backstage is an open framework for building developer portals. Prior to 1.14.6 and from 1.15.0 until 1.15.4, the @backstage/plugin-techdocs-node package insufficiently validates mkdocs.yml supplied by an authenticated user who can register or modify a TechDocs source. Unsafe Python YAML tags, markdown_extensions names and configuration, theme options, and extra_templates values can reach the documentation generator and cause unintended code execution. The resulting impact is limited to the files, credentials, network access, and other resources available to the TechDocs backend or build container. This issue is fixed in versions 1.14.6 and 1.15.4.

## Remediation

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