CVE-2026-106493 in Backstage
Summary
by MITRE • 10/07/2026
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.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified in Backstage prior to version 1.54.6 represents a critical path traversal flaw within its cloud storage catalog provider functionality. Backstage serves as an open framework for constructing developer portals, aggregating software metadata from various sources including local files and remote object stores such as Azure Blob Storage and AWS S3. The core issue stems from insufficient validation of object paths when these external providers are configured to ingest catalog descriptors. Specifically, the backend service failed to adequately sanitize or restrict file path inputs provided by principals who possess permissions to create or rename objects within the designated storage buckets. This lack of rigorous input validation allows an attacker with write access to a configured cloud storage source to manipulate the directory structure in a way that bypasses intended isolation boundaries.
From a technical perspective, this flaw enables unauthorized data exfiltration through path traversal techniques. By crafting specific object names or renaming existing objects to include relative path sequences such as dot-dot-slash sequences, an attacker can direct the Backstage backend to read catalog descriptors from locations outside the designated storage boundary. The scope of this access is constrained only by the permissions associated with the backend service account credentials configured for that particular cloud provider integration. Consequently, if the backend possesses broad read privileges across multiple buckets or directories within a cloud environment, an attacker could potentially access sensitive configuration files, internal documentation, or other metadata stored in adjacent or parent directories that were not intended to be part of the developer portal's catalog source.
The operational impact of this vulnerability is significant for organizations relying on Backstage for centralized software inventory and service discovery. An adversary exploiting this flaw can achieve unauthorized read access to sensitive information residing within the cloud storage infrastructure linked to the Backstage instance. This could lead to the exposure of internal architectural details, secret configurations embedded in catalog files, or other proprietary data that aids further reconnaissance efforts against the organization's infrastructure. While the vulnerability does not directly allow for remote code execution on the backend servers themselves, it serves as a powerful vector for information disclosure and lateral movement within cloud storage environments where access controls are loosely defined.
This issue aligns with CWE-22 Improper Limitation of a Pathname to a Restricted Directory, which describes vulnerabilities arising from insufficient validation of user-supplied input that specifies file paths or directories. In the context of attack frameworks such as MITRE ATT&CK, this behavior corresponds to techniques involving Data Staged and Collection via Cloud Storage APIs, where an attacker gathers data for exfiltration by accessing resources they should not have permission to view. The exploitation relies on the principle of least privilege being violated at the cloud storage level or misconfigured backend permissions that grant excessive read access beyond the specific bucket intended for catalog ingestion.
To mitigate this risk, organizations must upgrade Backstage to version 1.54.6 or later where the path validation logic has been strengthened to ensure object paths remain within their designated boundaries regardless of input manipulation. Additionally, administrators should review and tighten IAM policies associated with the backend service accounts used by Backstage for cloud storage integrations. It is crucial that these credentials are granted only the minimum necessary permissions required for reading catalog descriptors from specific buckets or prefixes, rather than broad read access across entire storage accounts. Regular auditing of object naming conventions within integrated storage sources can also help detect attempts to exploit path traversal mechanisms before they result in data exposure.