CVE-2026-106499: Backstage: Secret-derived values may be exposed in scaffolder task logs

Description

Backstage is an open framework for building developer portals. Prior to 4.1.0, the @backstage/plugin-scaffolder-backend package could expose secret-derived values in Scaffolder task logs. Deployments that configure sensitive scaffolder.defaultEnvironment.secrets and allow an attacker to create or modify Scaffolder templates are affected. A template author could cause secret-derived values used during template iteration to be persisted and exposed to users who can access the resulting task logs. This issue is fixed in version 4.1.0.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

Attack vector

Network

Complexity

Low

Privileges

High

User interaction

None

Confidentiality

High

Integrity

None

Availability

None

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)0.3% · higher than 19% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

BA

backstage · backstage

< 1.54.6 · source: vendor, NVD

PL

plugin-scaffolder-backend · @backstage

< 4.1.0 · source: vendor

BA

Backstage/plugin-scaffolder-backend · Linuxfoundation

before 4.1.0 · source: NVD