CVE-2026-106559: Backstage: Improper input validation in Confluence to Markdown scaffolder module
Impact
Insufficient input validation in the Confluence to Markdown scaffolder module could allow an attacker to influence file write operations during template execution. Exploitation requires a Backstage user to run a template that processes attacker-influenced Confluence content.
Patches
Patched in @backstage/plugin-scaffolder-backend-module-confluence-to-markdown version 0.3.25
Workarounds
If unable to update immediately:
- Restrict Confluence edit access to trusted users. - Review Confluence page content before running scaffolder templates against untrusted pages.
Other sources
Backstage is an open framework for building developer portals. Prior to 0.3.25, the @backstage/plugin-scaffolder-backend-module-confluence-to-markdown package is affected by improper input validation in confluence to markdown scaffolder module. Insufficient input validation in the Confluence to Markdown scaffolder module could allow an attacker to influence file write operations during template execution. Exploitation requires a Backstage user to run a template that processes attacker-influenced Confluence content. This issue is fixed in version 0.3.25.
— MITRE
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
Who is exposed to exploitation?
Exposure requires deployments using the @backstage/plugin-scaffolder-backend-module-confluence-to-markdown package before version 0.3.25, where a Backstage user can run a template that processes Confluence content influenced by an attacker.
What does an attacker need to exploit the issue?
An attacker needs to influence the Confluence content processed by a scaffolder template. A Backstage user must then run that template; the vulnerability does not describe exploitation without this user interaction.
What is the remediation?
Upgrade @backstage/plugin-scaffolder-backend-module-confluence-to-markdown to version 0.3.25 or later. The issue is fixed in 0.3.25.
How can teams reduce risk before upgrading?
Limit or avoid running templates that process attacker-influenced Confluence content. Restrict who can modify the relevant Confluence content and who can execute affected scaffolder templates.