CVE-2026-24046

HighCVSS 7.1

Published: 21/01/2026(UTC)Updated: 15/07/2026(UTC)Translated: 16/07/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.48%

38th percentile - higher than 38% of all known CVEs

Summary

Backstage is vulnerable to symlink-based path traversal attacks in Scaffolder actions and archive extraction utilities. An attacker with access to create and execute Scaffolder templates can read, delete, or write files outside the workspace.

Risk Assessment

The risk includes unauthorized reading of sensitive files (e.g., /etc/passwd, configurations, secrets), deletion of arbitrary files, and writing files outside the workspace, potentially compromising confidentiality, integrity, and availability.

Recommendation

Immediately upgrade @backstage/backend-defaults, @backstage/plugin-scaffolder-backend, and @backstage/plugin-scaffolder-node to patched versions. Additionally, restrict access to creating and executing Scaffolder templates and run Backstage in a containerized environment with limited filesystem access.

Other vulnerabilities in Backstage

CVE-2026-73563Medium
Backstage before version 0.29.2 has a vulnerability in the experimental dynamic client registration and client ID metadata document features in @backstage/plugin-auth-backend. Full-string glob matching can be bypassed, allowing an attacker-controlled redirect URI with a trusted hostname suffix in its path to pass the allowlist and receive an OAuth authorization code after a victim completes the flow. These features are experimental and disabled by default.

Original NVD description (English source)

Backstage is an open framework for building developer portals. Multiple Scaffolder actions and archive extraction utilities were vulnerable to symlink-based path traversal attacks. An attacker with access to create and execute Scaffolder templates could exploit symlinks to read arbitrary files via the `debug:log` action by creating a symlink pointing to sensitive files (e.g., `/etc/passwd`, configuration files, secrets); delete arbitrary files via the `fs:delete` action by creating symlinks pointing outside the workspace, and write files outside the workspace via archive extraction (tar/zip) containing malicious symlinks. This affects any Backstage deployment where users can create or execute Scaffolder templates. This vulnerability is fixed in `@backstage/backend-defaults` versions 0.12.2, 0.13.2, 0.14.1, and 0.15.0; `@backstage/plugin-scaffolder-backend` versions 2.2.2, 3.0.2, and 3.1.1; and `@backstage/plugin-scaffolder-node` versions 0.11.2 and 0.12.3. Users should upgrade to these versions or later. Some workarounds are available. Follow the recommendation in the Backstage Threat Model to limit access to creating and updating templates, restrict who can create and execute Scaffolder templates using the permissions framework, audit existing templates for symlink usage, and/or run Backstage in a containerized environment with limited filesystem access.