CVE-2026-106459: Backstage: Improper input validation in Sentry scaffolder actions
Impact
An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token.
Patches
Upgrade @backstage/plugin-scaffolder-backend-module-sentry to version 0.3.8 or later. The fixed package is available in Backstage v1.54.8 and Backstage v1.55.0.
The update removes custom action-level apiBaseUrl values. Move any such value to scaffolder.sentry.apiBaseUrl before upgrading.
Workarounds
- Disable the affected actions until the patched package is deployed. - Restrict scaffolder.action.execute permission for the affected Sentry actions to trusted users and templates.
Other sources
Backstage is an open framework for building developer portals. From 0.3.0 until 0.3.8, the @backstage/plugin-scaffolder-backend-module-sentry package is affected by improper input validation in sentry scaffolder actions. An authenticated internal user who can execute the affected actions may cause the backend to contact unintended destinations and disclose Sentry integration credentials. Subsequent impact depends on network reachability and the privileges granted to the configured token. This issue is fixed in version 0.3.8.
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-backend-module-sentryto a version that resolves this vulnerability.Fixed in 0.3.8 - Upgrade
Upgrade
@backstage/plugin-scaffolder-backend-module-sentryto a version that resolves this vulnerability.Fixed in 0.3.8 - Configuration
Move any action-level apiBaseUrl values to scaffolder.sentry.apiBaseUrl before upgrading.
Backstage Sentry scaffolder actions scaffolder.sentry.apiBaseUrl = Move any custom apiBaseUrl values here - Configuration
Restrict scaffolder.action.execute permission for the affected Sentry actions to trusted users and templates.
Backstage Sentry scaffolder actions scaffolder.action.execute = Restricted to trusted users and templates - Compensating control
Disable the affected Sentry actions until the patched package is deployed.
Event History
Frequently Asked Questions
Who can exploit this issue?
An authenticated internal user must be able to execute the affected Sentry scaffolder actions. The issue is therefore relevant to Backstage deployments where such action execution rights are granted to users.
What can an attacker do with successful exploitation?
They may cause the backend to contact unintended destinations and disclose Sentry integration credentials. The resulting impact depends on what network destinations the backend can reach and the privileges assigned to the configured token.
Which package versions are affected and what version fixes the issue?
Versions from 0.3.0 through before 0.3.8 of @backstage/plugin-scaffolder-backend-module-sentry are affected. Version 0.3.8 fixes the issue.