CVE-2026-106494: Backstage: Improper input validation in cloud storage URL readers
Backstage is an open framework for building developer portals. Prior to 0.17.8, the @backstage/backend-defaults package is affected by improper input validation in cloud storage url readers. An attacker with write access to a cloud storage bucket used by Backstage could craft object names that could collide with protected files in the output directory. In certain deployment configurations, this could lead to content injection. This issue is fixed in version 0.17.8.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
@backstage/backend-defaultsto a version that resolves this vulnerability.Fixed in 0.17.8
Event History
Frequently Asked Questions
Which deployments are exposed to content injection risk?
Deployments that use the affected cloud storage URL readers and a cloud storage bucket where an attacker can write objects may be exposed. The issue leads to content injection only in certain deployment configurations.
What level of access would an attacker need?
An attacker needs write access to a cloud storage bucket used by Backstage. They could then create object names that collide with protected files in the output directory.
What version contains the fix?
The issue is fixed in @backstage/backend-defaults version 0.17.8.