CVE-2026-29184 — @backstage/plugin-scaffol…
LOWCVE-2026-29184 is a low-severity (CVSS 2) CWE-532 vulnerability in @backstage/plugin-scaffolder-backend. A fix is available for @backstage/plugin-scaffolder-backend — see the affected versions and patch details below.
@backstage/plugin-scaffolder-backend Vulnerable to Potential Session Token Exfiltration via Log Redaction Bypass
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 CVE-2026-29184.
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/plugin-scaffolder-backendnpmDescription
Impact
A malicious scaffolder template can bypass the log redaction mechanism to exfiltrate secrets provided run through task event logs.
The attack requires:
- The ability to register a template in the catalog
- A victim who executes the malicious template
Patches
Patched in @backstage/plugin-scaffolder-backend version 3.1.4
Workarounds
- Implement a custom permission policy that restricts scaffolder.task.read so users can only read their own task logs
- Restrict who can register templates in the catalog to trusted users only
Resources
- Backstage Scaffolder permissions documentation: https://backstage.io/docs/permissions/plugin-authors/01-setup/
- Backstage Threat Model: https://backstage.io/docs/overview/threat-model/
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @backstage/plugin-scaffolder-backend | all versions | 3.1.4npm install @backstage/plugin-scaffolder-backend@3.1.4 |
Affected Products
backstage\/plugin-scaffolder-backendlinuxfoundationDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @backstage/plugin-scaffolder-backend, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @backstage/plugin-scaffolder-backend to 3.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-29184 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
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.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2026-29184 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-29184 in your dependencies?
Find it across npm, including transitive dependencies.