CVE-2026-106506: Backstage: Improper input validation in scaffolder task list ordering

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-06 · updated 2026-10-09
Weakness: CWE-202

Description

Backstage is an open framework for building developer portals. Prior to 4.1.0, the @backstage/plugin-scaffolder-backend package is affected by improper input validation in scaffolder task list ordering. An authenticated Backstage user with permission to create and read relevant scaffolder tasks may be able to infer confidential task data under specific conditions. Successful exploitation requires retained task secrets, visibility of a target task, knowledge of the secret structure, and repeated requests. This issue is fixed in version 4.1.0.

Affected products

backstage: before 1.54.6 — fixed in 1.54.6
@backstage plugin-scaffolder-backend: before 4.1.0 — fixed in 4.1.0

How to fix

Upgrade to a fixed version: backstage 1.54.6; @backstage plugin-scaffolder-backend 4.1.0. Check the vendor advisory for mitigations.

References

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