CVE-2026-24046: Backstage has a Possible Symlink Path Traversal in Scaffolder Actions
Impact
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:
1. Read arbitrary files via the debug:log action by creating a symlink pointing to sensitive files (e.g., /etc/passwd, configuration files, secrets) 2. Delete arbitrary files via the fs:delete action by creating symlinks pointing outside the workspace 3. 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.
Patches
This vulnerability is fixed in the following package versions:
- @backstage/backend-defaults version 0.12.2, 0.13.2, 0.14.1, 0.15.0 - @backstage/plugin-scaffolder-backend version 2.2.2, 3.0.2, 3.1.1 - @backstage/plugin-scaffolder-node version 0.11.2, 0.12.3
Users should upgrade to these versions or later.
Workarounds
- 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 - Run Backstage in a containerized environment with limited filesystem access
References
- CWE-59: Improper Link Resolution Before File Access - OWASP Path Traversal
Other sources
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.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-nodeto a version that resolves this vulnerability.Fixed in 0.12.3 - Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-nodeto a version that resolves this vulnerability.Fixed in 0.11.2 - Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 3.1.1 - Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 3.0.2 - Upgrade
Upgrade
npm/@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 2.2.2 - Upgrade
Upgrade
npm/@backstage/backend-defaultsto a version that resolves this vulnerability.Fixed in 0.14.1 - Upgrade
Upgrade
npm/@backstage/backend-defaultsto a version that resolves this vulnerability.Fixed in 0.13.2 - Upgrade
Upgrade
npm/@backstage/backend-defaultsto a version that resolves this vulnerability.Fixed in 0.12.2 - Upgrade
Upgrade
@backstage/backend-defaultsto a version that resolves this vulnerability.Fixed in 0.15.0 - Upgrade
Upgrade
@backstage/backend-defaultsto a version that resolves this vulnerability.Fixed in 0.14.1 - Upgrade
Upgrade
@backstage/backend-defaultsto a version that resolves this vulnerability.Fixed in 0.13.2 - Upgrade
Upgrade
@backstage/backend-defaultsto a version that resolves this vulnerability.Fixed in 0.12.2 - Upgrade
Upgrade
@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 3.1.1 - Upgrade
Upgrade
@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 3.0.2 - Upgrade
Upgrade
@backstage/plugin-scaffolder-backendto a version that resolves this vulnerability.Fixed in 2.2.2 - Upgrade
Upgrade
@backstage/plugin-scaffolder-nodeto a version that resolves this vulnerability.Fixed in 0.12.3 - Upgrade
Upgrade
@backstage/plugin-scaffolder-nodeto a version that resolves this vulnerability.Fixed in 0.11.2 - Compensating control
Follow the Backstage Threat Model recommendation to limit access to creating and updating Scaffolder templates and restrict who can create and execute Scaffolder templates using the permissions framework.
- Compensating control
Audit existing Scaffolder templates for symlink usage.
- Compensating control
Run Backstage in a containerized environment with limited filesystem access.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-24046?
The severity of CVE-2026-24046 is considered to be high due to the potential for symlink-based path traversal attacks.
How do I fix CVE-2026-24046?
To fix CVE-2026-24046, you should upgrade to versions 0.12.3 or later for @backstage/plugin-scaffolder-node, 3.1.1 or later for @backstage/plugin-scaffolder-backend, and 0.14.1 or later for @backstage/backend-defaults.
What types of software are affected by CVE-2026-24046?
CVE-2026-24046 affects multiple versions of @backstage/plugin-scaffolder-backend, @backstage/plugin-scaffolder-node, and @backstage/backend-defaults.
Can an attacker exploit CVE-2026-24046 remotely?
Yes, an attacker with access to create and execute Scaffolder templates can exploit CVE-2026-24046 remotely using symlink attacks.
What are the potential impacts of CVE-2026-24046?
The potential impacts of CVE-2026-24046 include unauthorized access to sensitive files or directories on the server.