Plugin scaffolder backend module bitbucket cloud: Backstage has iImproper filesystem validation in Bitbucket pull-request scaffolder actions (CVE-2026-106486)
Description
CVE-2026-106486 is a high-severity vulnerability in the Backstage plugin scaffolder backend modules for Bitbucket Cloud and Bitbucket Server. It allows an authenticated user with limited privileges to influence filesystem paths outside the intended working directory when executing certain templates. This can lead to compromise of backend confidentiality, integrity, or availability depending on deployment specifics. Fixed versions are 0.3.10 for the Bitbucket Cloud module and 0.2.25 for the Bitbucket Server module.
CVSS v3.1
Score 8.5high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud and bitbucket-server modules arises from improper filesystem validation in Bitbucket pull-request scaffolder actions. An authenticated user able to execute eligible templates and influence allowed Bitbucket repositories can cause filesystem path traversal outside the expected working area. This flaw can impact backend confidentiality, integrity, and availability. The issue is tracked as CVE-2026-106486 with a CVSS 3.1 score of 8.5 (high severity).
Potential Impact
An authenticated user with permission to execute certain scaffolder templates can manipulate filesystem paths to access or modify files outside the intended scope. This can lead to unauthorized disclosure, modification, or deletion of backend files, potentially compromising system confidentiality, integrity, and availability.
Mitigation Recommendations
A patch is available in @backstage/plugin-scaffolder-backend-module-bitbucket-cloud version 0.3.10 and @backstage/plugin-scaffolder-backend-module-bitbucket-server version 0.2.25. Users should upgrade to these versions promptly. As a workaround, restrict execution of affected scaffolder templates to trusted users and avoid using templates that accept user-controlled target repositories for these actions.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-g8rx-f7m5-7794
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-106486"]
- Ecosystems
- ["npm"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6ac6bfff2cdf04f6568291ab
Added to database: 10/07/2026, 21:56:15 UTC
Last enriched: 10/07/2026, 22:14:25 UTC
Last updated: 10/07/2026, 22:14:25 UTC
Views: 6
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