CVE-2026-106505 is a high-severity (CVSS 7.7) CWE-426 vulnerability in @backstage/plugin-techdocs-node. A fix is available for @backstage/plugin-techdocs-node — see the affected versions and patch details below.
Backstage: Bypass of MkDocs configuration sanitizer in TechDocs backend
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-106505.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-106505 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
@backstage/plugin-techdocs-nodeReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Users with the ability to commit changes to a repository that uses TechDocs can circumvent the MkDocs configuration file sanitizer introduced in response to CVE-2026-25153 and execute arbitrary code on the TechDocs backend host during documentation generation.
Patches
Patched in@backstage/plugin-techdocs-node version 1.15.4
Workarounds
If you cannot upgrade immediately:
- Use Docker mode with restricted access: Configure TechDocs with
runIn: dockerinstead ofrunIn: local. This provides container isolation, though it does not fully mitigate the risk. - Limit repository write access to trusted parties, since exploitation requires the ability to commit files to a repository with TechDocs enabled.
- Review incoming changes to MkDocs configuration files as part of your code review process.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @backstage/plugin-techdocs-node | all versions | 1.15.4npm install @backstage/plugin-techdocs-node@1.15.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @backstage/plugin-techdocs-node, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @backstage/plugin-techdocs-node to 1.15.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-106505 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This vulnerability is rated as Moderate because successful exploitation requires authenticated access and commit permissions to integrated documentation repositories, limiting the threat scope to authorized users. In affected Red Hat Developer Hub and Ansible Automation Platform environments where documentation…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for CVE-2026-106505 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-106505 in your dependencies?
Find it across npm, including transitive dependencies.