Linuxfoundation: >> Backstage Security Vulnerabilities
Backstage is an open framework for building developer portals. Prior to 3.5.1, 3.6.2, 3.7.2, 3.8.2 and 3.9.1, the @backstage/plugin-catalog-backend package is affected by improper url validation in catalog entity placeholder resolution. An authenticated Backstage user could craft a catalog entity with placeholder directives that reference resources outside the entity's source repository. Under certain configurations, this could allow access to data not intended to be available to the user. This issue is fixed in versions 3.5.1, 3.6.2, 3.7.2, 3.8.2 and 3.9.1.
CVSS Score
7.7
EPSS Score
0.003
Published
2026-10-06
Backstage is an open framework for building developer portals. Prior to 4.1.0, the @backstage/plugin-scaffolder-backend package could expose secret-derived values in Scaffolder task logs. Deployments that configure sensitive scaffolder.defaultEnvironment.secrets and allow an attacker to create or modify Scaffolder templates are affected. A template author could cause secret-derived values used during template iteration to be persisted and exposed to users who can access the resulting task logs. This issue is fixed in version 4.1.0.
CVSS Score
4.9
EPSS Score
0.003
Published
2026-10-06
Backstage is an open framework for building developer portals. Prior to 0.6.17, the @backstage/plugin-proxy-backend package is affected by improper input validation in proxy-backend. An authenticated Backstage user could craft a request URL that causes the proxy-backend to forward the request to a path outside the configured base path on the target server. This is limited to target servers already configured as proxy endpoints and requires Backstage authentication by default. This issue is fixed in version 0.6.17.
CVSS Score
6.4
EPSS Score
0.003
Published
2026-10-06
Backstage is an open framework for building developer portals. Prior to 0.16.1 and 0.17.8, the @backstage/backend-defaults package is affected by improper preservation of access restrictions during service credential delegation. An external service credential configured with access restrictions (e.g., read-only) could bypass those restrictions by routing requests through plugin delegation paths. This could allow a restricted service to perform operations beyond its intended scope, including write operations on plugins it was restricted to read-only access for. This issue is fixed in versions 0.16.1 and 0.17.8.
CVSS Score
7.6
EPSS Score
0.002
Published
2026-10-06
Backstage is an open framework for building developer portals. Prior to 1.54.6, cloud storage catalog providers did not sufficiently validate object paths. A principal able to create or rename objects in a configured Azure Blob Storage or AWS S3 catalog source could cause catalog descriptors to be read from outside the intended storage boundary, limited to locations reachable with the backend's configured credentials. This issue is fixed in 1.54.6.
CVSS Score
3.0
EPSS Score
0.003
Published
2026-10-06
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.
CVSS Score
4.4
EPSS Score
0.003
Published
2026-10-06
Backstage is an open framework for building developer portals. Prior to 1.54.6, scaffolder source-control actions may not consistently enforce intended credential boundaries. An authenticated user could cause an affected action to fall back to broader integration credentials and perform operations with more access than intended. This issue is fixed in 1.54.6 when operators also enable scaffolder.requireScmUserCredentials after upgrading.
CVSS Score
6.4
EPSS Score
0.002
Published
2026-10-06
Backstage is an open framework for building developer portals. Prior to 0.8.7, the @backstage/plugin-catalog-backend-module-gitlab package is affected by improper authorization in gitlab organizational user ingestion. Deployments that enable GitLab organization event ingestion and rely on scoped catalog users as an access boundary may admit an unintended catalog identity. Depending on sign-in and permission configuration, this may allow unauthorized access with the permissions of a standard authenticated user. This issue is fixed in version 0.8.7.
CVSS Score
5.4
EPSS Score
0.002
Published
2026-10-06
Backstage is an open framework for building developer portals. Prior to 0.3.10 in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud and 0.2.25 in @backstage/plugin-scaffolder-backend-module-bitbucket-server, the Bitbucket pull-request Scaffolder actions did not sufficiently validate filesystem paths. An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect paths outside the expected working area, potentially compromising backend confidentiality, integrity, or availability. This issue is fixed in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud 0.3.10 and @backstage/plugin-scaffolder-backend-module-bitbucket-server 0.2.25.
CVSS Score
8.5
EPSS Score
0.004
Published
2026-10-06
Backstage is an open framework for building developer portals. Prior to 0.21.10, the @backstage/plugin-kubernetes-backend package is affected by unsupported catalog cluster authentication mode in kubernetes backend. Deployments using catalog cluster discovery may be affected when catalog contributors can create or modify kubernetes-cluster Resource entities. With the required endpoint permissions and pod RBAC, the backend can use its local in-cluster identity, potentially exposing Kubernetes resources readable by that identity. The credential is used only with the local in-cluster API endpoint and is not sent to the catalog-supplied endpoint. This issue is fixed in version 0.21.10.
CVSS Score
3.5
EPSS Score
0.003
Published
2026-10-06