CVE-2026-106563

Backstage: Improper entity validation in deprecated Kubernetes services endpoint

MEDIUM
6.5
CVSS Score
Published: October 7, 2026 at 02:56 PM UTC
Updated: October 16, 2026 at 02:50 PM UTC
4 products affected across 2 vendorsBackstagebackstage\/plugin-kubernetes-backendBackstage

Using backstage by backstage?

Get instant alerts when new vulnerabilities affect backstage - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Backstage is an open framework for building developer portals. Prior to 0.21.8, the @backstage/plugin-kubernetes-backend package is affected by improper entity validation in deprecated kubernetes services endpoint. An authenticated user with Kubernetes read permissions could access Kubernetes workload data beyond their intended scope by supplying crafted entity data to the deprecated services endpoint. The exposure is limited to read-only access to Kubernetes object metadata across configured clusters. This issue is fixed in version 0.21.8.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

References (3)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/backstage/backstage/security/advisories/GHSA-r9ph-3637-55px
x_refsource_MISCPatchRelease Notes
Source: cverecord
https://github.com/backstage/backstage/releases/tag/v1.54.1

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20CWE-862

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card