Template Secret leakage in logs in Scaffolder when using fetch:template

Exploitation

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

CVSS

2.6 · CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:N/A:N

EPSS

• CVE-2025-55285: 0.24% estimated exploitation activity in the next 30 days; percentile 15.59 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

A logging flaw in Backstage Scaffolder’s fetch:template action up to @backstage/plugin-scaffolder-backend 2.1.0 may write template secrets to logs. The action emitted a duplicate, pre-redaction copy of input parameters, so values provided via the {{ secrets }} bag could appear in local/server logs when the action ran. Exploitation requires use of the secrets argument and access to Scaffolder/build logs; integrity and availability are unaffected. Fix: upgrade to 2.1.1, which removes the duplicate log path and ensures secrets are redacted. Mitigation: avoid passing {{ secrets }} to fetch:template if upgrade is not possible. Open an issue in the Backstage repository Visit our Discord, linked to in Backstage README

Published by the source

15 Aug 2025, 18:43 UTC

Last modified by the source

26 Sep 2025, 17:19 UTC

Source last checked

26 Oct 2026, 12:38 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-3x3q-ghcp-whf7

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-3x3q-ghcp-whf7

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# Patch Next advisory brief: CVE-2025-55285

Advisory: Template Secret leakage in logs in Scaffolder when using `fetch:template`
IDs: CVE-2025-55285, GHSA-3x3q-ghcp-whf7
Record: https://patchnext.com/advisories/cve-2025-55285 (revision 2, source checked 26 Oct 2026, 12:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.6)
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 2.1.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @backstage/plugin-scaffolder-backend: affected <= 2.1.0; fixed in 2.1.1

## 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-3x3q-ghcp-whf7 (OSV record GHSA-3x3q-ghcp-whf7 lists affected ranges: npm @backstage/plugin-scaffolder-backend >=0 <2.1.1 (fixed))
- Verified: https://github.com/advisories/GHSA-3x3q-ghcp-whf7 (GitHub-reviewed advisory GHSA-3x3q-ghcp-whf7 lists affected ranges: npm @backstage/plugin-scaffolder-backend >=0 <=2.1.0)

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