RCE vulnerability affecting v1beta3 templates in @backstage/plugin-scaffolder-backend

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

The templating library used by the scaffolder backend assumes that templates are trusted which is an undesired property of the scaffolder-backend. This has now been mitigated by sandboxing the template code execution. Impact A malicious actor with write access to a registered scaffolder template could manipulate the template in a way that allows for remote code execution on the scaffolder-backend instance. This was only exploitable in the template yaml definition itself and not by user input data. Patches This is vulnerability is patched in version 0.15.14 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

Published by the source

1 Dec 2021, 18:29 UTC

Last modified by the source

9 Jan 2023, 05:05 UTC

Source last checked

26 Oct 2026, 12:16 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-2g8g-63j4-9w3r

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-2g8g-63j4-9w3r

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# Patch Next advisory brief: GHSA-2g8g-63j4-9w3r

Advisory: RCE vulnerability affecting v1beta3 templates in @backstage/plugin-scaffolder-backend
IDs: GHSA-2g8g-63j4-9w3r
Record: https://patchnext.com/advisories/ghsa-2g8g-63j4-9w3r (revision 2, source checked 26 Oct 2026, 12:16 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @backstage/plugin-scaffolder-backend 0.15.14. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @backstage/plugin-scaffolder-backend: affected < 0.15.14; fixed in 0.15.14

## Suggested inspection (read-only)
- `npm ls @backstage/plugin-scaffolder-backend --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @backstage/plugin-scaffolder-backend.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-2g8g-63j4-9w3r (OSV record GHSA-2g8g-63j4-9w3r lists affected ranges: npm @backstage/plugin-scaffolder-backend >=0 <0.15.14 (fixed))
- Verified: https://github.com/advisories/GHSA-2g8g-63j4-9w3r (GitHub-reviewed advisory GHSA-2g8g-63j4-9w3r lists affected ranges: npm @backstage/plugin-scaffolder-backend >=0 <0.15.14)

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