CVE-2026-106486 is a high-severity (CVSS 8.5) Path Traversal vulnerability in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud. A fix is available for @backstage/plugin-scaffolder-backend-module-bitbucket-cloud — see the affected versions and patch details below.
Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-106486.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-106486 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
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-backend-module-bitbucket-cloudnpm@backstage/plugin-scaffolder-backend-module-bitbucket-servernpmDescription
Backstage is an open framework for building developer portals. Prior to 0.3.10 in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud and 0.2.25 in @backstage/plugin-scaffolder-backend-module-bitbucket-server, the Bitbucket pull-request Scaffolder actions did not sufficiently validate filesystem paths. An authenticated user who can execute an eligible template and influence an allowed Bitbucket repository could affect paths outside the expected working area, potentially compromising backend confidentiality, integrity, or availability. This issue is fixed in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud 0.3.10 and @backstage/plugin-scaffolder-backend-module-bitbucket-server 0.2.25.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @backstage/plugin-scaffolder-backend-module-bitbucket-cloud | all versions | 0.3.10npm install @backstage/plugin-scaffolder-backend-module-bitbucket-cloud@0.3.10 |
| 📦npm | @backstage/plugin-scaffolder-backend-module-bitbucket-server | all versions | 0.2.25npm install @backstage/plugin-scaffolder-backend-module-bitbucket-server@0.2.25 |
Affected Products
backstagelinuxfoundationbackstage\/plugin-scaffolder-backend-module-bitbucket-cloudlinuxfoundationbackstage\/plugin-scaffolder-backend-module-bitbucket-serverlinuxfoundationDetection & 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-module-bitbucket-cloud, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @backstage/plugin-scaffolder-backend-module-bitbucket-cloud to 0.3.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-106486 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.
Red Hat Product Security rates this vulnerability as Important because an authenticated user capable of triggering software templates can exploit path traversal to manipulate files on the underlying host, potentially escaping the workspace boundary and affecting critical backend services. In Red Hat Developer Hub, the…
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-2026-106486 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-106486 in your dependencies?
Find it across npm, including transitive dependencies.