Backstage has a Possible Symlink Path Traversal in Scaffolder ActionsGHSA-rq6q-wr2q-7pgp
HIGHFix: backstage/backstage@c641c14GHSA-rq6q-wr2q-7pgp is a high-severity (CVSS 7.1) Path Traversal vulnerability in @backstage/backend-defaults. A fix is available for @backstage/backend-defaults — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-rq6q-wr2q-7pgp.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@backstage/backend-defaultsnpmDescription
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:
- Read arbitrary files via the
debug:logaction by creating a symlink pointing to sensitive files (e.g.,/etc/passwd, configuration files, secrets) - Delete arbitrary files via the
fs:deleteaction by creating symlinks pointing outside the workspace - 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-defaultsversion 0.12.2, 0.13.2, 0.14.1, 0.15.0@backstage/plugin-scaffolder-backendversion 2.2.2, 3.0.2, 3.1.1@backstage/plugin-scaffolder-nodeversion 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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @backstage/backend-defaults | all versions | 0.12.2npm install @backstage/backend-defaults@0.12.2 |
| 📦npm | @backstage/backend-defaults | ≥ 0.13.0&&< 0.13.2 | 0.13.2npm install @backstage/backend-defaults@0.13.2 |
| 📦npm | @backstage/backend-defaults | ≥ 0.14.0&&< 0.14.1 | 0.14.1npm install @backstage/backend-defaults@0.14.1 |
| 📦npm | @backstage/plugin-scaffolder-backend | all versions | 2.2.2npm install @backstage/plugin-scaffolder-backend@2.2.2 |
| 📦npm | @backstage/plugin-scaffolder-backend | ≥ 3.0.0&&< 3.0.2 | 3.0.2npm install @backstage/plugin-scaffolder-backend@3.0.2 |
| 📦npm | @backstage/plugin-scaffolder-backend | ≥ 3.1.0&&< 3.1.1 | 3.1.1npm install @backstage/plugin-scaffolder-backend@3.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @backstage/backend-defaults, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @backstage/backend-defaults to 0.12.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rq6q-wr2q-7pgp is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
To exploit this issue, an attacker needs to have access to create and execute Scaffolder actions, specifically the debug:log, fs:delete actions and archive extractions, limiting the exposure of this flaw. Additionally, file systems operations are constrained by the permissions of the process, limiting the impact to…
To mitigate this issue, consider implementing strict access controls for Backstage Scaffolder templates. Restrict the ability to create and execute Scaffolder templates to trusted users only, utilizing the Backstage permissions framework. Additionally, audit existing templates for any symlink usage and consider running Backstage within a containerized environment with a highly restricted filesystem to limit potential impact.Source: Red Hat security advisory for GHSA-rq6q-wr2q-7pgp (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Developer Hub 1.8 | rhdh/rhdh-hub-rhel9:1774545605 | RHSA-2026:6174 |
| Red Hat Developer Hub 1.9 | rhdh/rhdh-hub-rhel9:1775140647 | RHSA-2026:6802 |
Frequently Asked Questions
Is GHSA-rq6q-wr2q-7pgp in your dependencies?
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