CVE-2026-106498

High

Description

Backstage is an open framework for building developer portals. Prior to 3.5.1, 3.6.2, 3.7.2, 3.8.2 and 3.9.1, the @backstage/plugin-catalog-backend package is affected by improper url validation in catalog entity placeholder resolution. An authenticated Backstage user could craft a catalog entity with placeholder directives that reference resources outside the entity's source repository. Under certain configurations, this could allow access to data not intended to be available to the user. This issue is fixed in versions 3.5.1, 3.6.2, 3.7.2, 3.8.2 and 3.9.1.

SeverityHigh
CVSS7.7
Exploit probability—
ProductLinuxfoundation Backstage Plugin-catalog-backend
PublishedOct 6, 2026
First seenOct 6, 2026

How to fix

Update
  • linuxfoundation backstage_plugin-catalog-backend3.5.1, 3.6.2, 3.7.2, 3.8.2, 3.9.1 or later
  • linuxfoundation backstage1.49.6, 1.50.5, 1.51.3, 1.53.2, 1.54.6 or later
  • @backstage/plugin-catalog-backend3.9.1 or later

Affected products

ProductAffected versionsFixed in
linuxfoundation backstage_plugin-catalog-backendv < 3.5.1, 3.6.0 ≤ v < 3.6.2, 3.7.0 ≤ v < 3.7.2, 3.8.0 ≤ v < 3.8.2, 3.9.0 ≤ v < 3.9.13.5.1, 3.6.2, 3.7.2, 3.8.2, 3.9.1
linuxfoundation backstagev < 1.49.6, 1.50.0 ≤ v < 1.50.5, 1.51.0 ≤ v < 1.51.3, 1.52.0 ≤ v < 1.53.2, 1.54.0 ≤ v < 1.54.61.49.6, 1.50.5, 1.51.3, 1.53.2, 1.54.6
@backstage/plugin-catalog-backendnpmv < 3.9.13.9.1

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CVE-2026-106498 · Linuxfoundation Backstage Plugin-catalog-backend · Dark Radar