What’s Vulnerable › Vulnerabilities

CVE-2021-32662: TechDocs mkdocs.yml path traversal

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-06-03 · updated 2026-06-17
• Weakness: CWE-22

Description

Backstage is an open platform for building developer portals, and techdocs-common contains common functionalities for Backstage's TechDocs. In `@backstage/techdocs-common` versions prior to 0.6.3, a malicious actor could read sensitive files from the environment where TechDocs documentation is built and published by setting a particular path for `docs_dir` in `mkdocs.yml`. These files would then be available over the TechDocs backend API. This vulnerability is mitigated by the fact that an attacker would need access to modify the `mkdocs.yml` in the documentation source code, and would also need access to the TechDocs backend API. The vulnerability is patched in the `0.6.3` release of `@backstage/techdocs-common`.

Affected products

• backstage: before 0.6.3 — fixed in 0.6.3

How to fix

Upgrade to a fixed version: backstage 0.6.3. Check the vendor advisory for mitigations.

References

• https://github.com/backstage/backstage/commit/8cefadca04cbf01d0394b0cb1983247e5f1d6208
• https://github.com/backstage/backstage/releases/tag/release-2021-05-27
• https://github.com/backstage/backstage/security/advisories/GHSA-pgf8-28gg-vpr6
• https://github.com/backstage/backstage/commit/8cefadca04cbf01d0394b0cb1983247e5f1d6208
• https://github.com/backstage/backstage/releases/tag/release-2021-05-27
• https://github.com/backstage/backstage/security/advisories/GHSA-pgf8-28gg-vpr6

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