CVE-2021-32662 TechDocs mkdocs.yml path traversal
Attackers with source code access can read sensitive files via path traversal in mkdocs.yml configuration, exposing data through the TechDocs API.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-32662?
CVE-2021-32662 is a medium-severity path traversal vulnerability in Linuxfoundation Backstage, published on 3 Jun 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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`.
Weakness: CWE-22
Which versions are affected by CVE-2021-32662?
2 open source packages ship an affected version, including @backstage/techdocs-common. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@backstage/techdocs-common npm | All versions | 0.6.3 |
@backstage/techdocs-common npm | All versions | 0.6.3 |
Products include Linuxfoundation Backstage.
How do I fix CVE-2021-32662?
Upgrade @backstage/techdocs-common to 0.6.3 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2021-32662 being exploited?
There is no known exploitation of CVE-2021-32662 in the wild and no public exploit code.
Other vulnerabilities in Linuxfoundation Backstage
- CVE-2026-106501 Backstage: Sensitive information exposure in Scaffolder
- CVE-2026-106558 Backstage: Improper validation of TechDocs MkDocs configuration
- CVE-2026-88064 Backstage: Improper input validation in TechDocs MkDocs configuration
- CVE-2026-106459 Backstage: Improper input validation in Sentry scaffolder actions
- CVE-2026-106486 Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Sources
Also known as GHSA-pgf8-28gg-vpr6.