CVE-2021-41151
Path Traversal in @backstage/plugin-scaffolder-backend
Backstage is an open platform for building developer portals. In affected versions A malicious actor could read sensitive files from the environment where Scaffolder Tasks are run. The attack is executed by crafting a custom Scaffolder template with a github:publish:pull-request action and a particular source path. When the template is executed the sensitive files would be included in the published pull request. This vulnerability is mitigated by the fact that an attacker would need access to create and register templates in the Backstage catalog, and that the attack is very visible given that the exfiltration happens via a pull request. The vulnerability is patched in the 0.15.9 release of @backstage/plugin-scaffolder-backend.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Path Traversal in @backstage/plugin-scaffolder-backend
Backstage is an open platform for building developer portals. In affected versions A malicious actor could read sensitive files from the environment where Scaffolder Tasks are run. The attack is executed by crafting a custom Scaffolder template with a github:publish:pull-request action and a particular source path. When the template is executed the sensitive files would be included in the published pull request. This vulnerability is mitigated by the fact that an attacker would need access to create and register templates in the Backstage catalog, and that the attack is very visible given that the exfiltration happens via a pull request. The vulnerability is patched in the 0.15.9 release of @backstage/plugin-scaffolder-backend.
- Record
CVE-2021-41151- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2021-2243
Backstage is an open platform for building developer portals. In affected versions A malicious actor could read sensitive files from the environment where Scaffolder Tasks are run. The attack is executed by crafting a custom Scaffolder template with a github:publish:pull-request action and a particular source path. When the template is executed the sensitive files would be included in the published pull request. This vulnerability is mitigated by the fact that an attacker would need access to create and register templates in the Backstage catalog, and that the attack is very visible given that the exfiltration happens via a pull request. The vulnerability is patched in the 0.15.9 release of @backstage/plugin-scaffolder-backend.
- Record
EUVD-2021-2243- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-pvv8-8fx9-h673
Path Traversal in @backstage/plugin-scaffolder-backend
Impact
A malicious actor could read sensitive files from the environment where Scaffolder tasks are run. The attack is executed by crafting a custom Scaffolder template with a publish:github:pull-request action using a particular source path. When the template is executed the sensitive files would be included in the published pull request.
This vulnerability is mitigated by the fact that an attacker would need access to create and register templates in the Backstage catalog, and that the attack is very visible given that the exfiltration happens via a pull request.
Patches
The vulnerability is patched in the 0.15.9 release of @backstage/plugin-scaffolder-backend.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the Backstage repository
- Visit our chat, linked to in Backstage README
- Record
GHSA-pvv8-8fx9-h673- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
Backstage is an open platform for building developer portals. In affected versions A malicious actor could read sensitive files from the environment where Scaffolder Tasks are run. The attack is executed by crafting a custom Scaffolder template with a github:publish:pull-request action and a particular source path. When the template is executed the sensitive files would be included in the published pull request. This vulnerability is mitigated by the fact that an attacker would need access to create and register templates in the Backstage catalog, and that the attack is very visible given that the exfiltration happens via a pull request. The vulnerability is patched in the 0.15.9 release of @backstage/plugin-scaffolder-backend.
- Record
CVE-2021-41151- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N - CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 4.0 Medium
AV:N/AC:L/Au:S/C:P/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
Backstage is an open platform for building developer portals. In affected versions A malicious actor could read sensitive files from the environment where Scaffolder Tasks are run. The attack is executed by crafting a custom Scaffolder template with a github:publish:pull-request action and a particular source path. When the template is executed the sensitive files would be included in the published pull request. This vulnerability is mitigated by the fact that an attacker would need access to create and register templates in the Backstage catalog, and that the attack is very visible given that the exfiltration happens via a pull request. The vulnerability is patched in the 0.15.9 release of @backstage/plugin-scaffolder-backend.
- Record
CVE-2021-41151- CVSS 3.1
- 4.9 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVGHSA-pvv8-8fx9-h673
Path Traversal in @backstage/plugin-scaffolder-backend
Impact
A malicious actor could read sensitive files from the environment where Scaffolder tasks are run. The attack is executed by crafting a custom Scaffolder template with a publish:github:pull-request action using a particular source path. When the template is executed the sensitive files would be included in the published pull request.
This vulnerability is mitigated by the fact that an attacker would need access to create and register templates in the Backstage catalog, and that the attack is very visible given that the exfiltration happens via a pull request.
Patches
The vulnerability is patched in the 0.15.9 release of @backstage/plugin-scaffolder-backend.
For more information
If you have any questions or comments about this advisory:
- Open an issue in the Backstage repository
- Visit our chat, linked to in Backstage README
- Record
GHSA-pvv8-8fx9-h673- CVSS 3.1
- 6.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
@backstage/plugin-scaffolder-backendnpm |
0.9.4 up to 0.15.9 | 0.15.9 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-41151 is a medium vulnerability (CVSS 6.8) in Backstage, published October 18, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.31%, the 70th percentile. Fixed in @backstage/plugin-scaffolder-backend 0.15.9.
References
github.com/backstage/backstage/security/advisories/GHSA-pvv8-8fx9-h673
nvd.nist.gov/vuln/detail/CVE-2021-41151