CVE intelligence and bounded remediation

CVE-2026-25152 — Linuxfoundation Backstage security vulnerability

Medium CVSS 6.5

Backstage is an open framework for building developer portals, and @backstage/plugin-techdocs-node provides common node.js functionalities for TechDocs. In versions of @backstage/plugin-techdocs-node prior to 1.13.11 and 1.14.1, a path traversal vulnerability in the TechDocs local generator allows attackers to read arbitrary files from the host filesystem when Backstage is configured with `techdocs.generator.runIn: local`. When processing documentation from untrusted sources, symlinks within the docs directory are followed by MkDocs during the build process. File contents are embedded into generated HTML and exposed to users who can view the documentation. This vulnerability is fixed in` @backstage/plugin-techdocs-node` versions 1.13.11 and 1.14.1. Some workarounds are available. Switch to `runIn: docker` in `app-config.yaml` and/or restrict write access to TechDocs source repositories to trusted users only.

Severity
Medium
CVSS
6.5 (3.1)
Published
2026-01-30
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-22

Affected products

  • linuxfoundation / backstage

Showing 1 representative product identities from 2 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Path traversal, unsafe upload, and file handling

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Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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