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

Low severity GitHub Reviewed Published Aug 15, 2025 in backstage/backstage • Updated Sep 26, 2025

Package

npm @backstage/plugin-scaffolder-backend (npm)

Affected versions

<= 2.1.0

Patched versions

2.1.1

Description

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.

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References

@benjdlambert benjdlambert published to backstage/backstage Aug 15, 2025
Published by the National Vulnerability Database Aug 15, 2025
Published to the GitHub Advisory Database Aug 15, 2025
Reviewed Aug 15, 2025
Last updated Sep 26, 2025

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
High
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:N/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(9th percentile)

Weaknesses

Insertion of Sensitive Information into Log File

Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information. Learn more on MITRE.

CVE ID

CVE-2025-55285

GHSA ID

GHSA-3x3q-ghcp-whf7

Source code

Credits

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