CVE-2026-106501: Backstage: Sensitive information exposure in Scaffolder
Impact
An authenticated Backstage user who can read another user's Scaffolder task may receive internal execution data. In deployments where that data contains credentials for an external service, this may permit disclosure and unauthorized changes in that external service.
Patches
Patched in @backstage/plugin-scaffolder-backend version 4.1.0
Workarounds
- Configure scaffolder.task.read with the isTaskOwner condition so users can only read tasks they created. - Restrict affected integrations and workflows to trusted operators until an upgrade is available.
Other sources
Backstage is an open framework for building developer portals. Prior to 3.3.1, 3.4.1, 4.0.3 and 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by sensitive information exposure in scaffolder. An authenticated Backstage user who can read another user's Scaffolder task may receive internal execution data. In deployments where that data contains credentials for an external service, this may permit disclosure and unauthorized changes in that external service. This issue is fixed in versions 3.3.1, 3.4.1, 4.0.3 and 4.1.0.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 4.1.0 - Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 4.0.3 - Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 3.4.1 - Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 3.3.1 - Upgrade
Upgrade
@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 4.1.0 - Configuration
Configure scaffolder.task.read with the isTaskOwner condition so users can only read tasks they created.
Backstage Scaffolder scaffolder.task.read = isTaskOwner - Compensating control
Restrict affected integrations and workflows to trusted operators until an upgrade is available.
Event History
Frequently Asked Questions
Who can exploit this issue?
An authenticated Backstage user who is able to read another user's Scaffolder task can access that task's internal execution data.
When does the exposure lead to impact beyond Backstage?
The issue can expose credentials when Scaffolder execution data contains credentials for an external service. Those credentials may allow disclosure of information or unauthorized changes in that external service.
Which package versions contain fixes?
Fixed versions are 3.3.1, 3.4.1, 4.0.3, and 4.1.0 of @backstage/plugin-scaffolder-backend.