How severe is CVE-2026-106563?

CVE-2026-106563 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-106563?

CVE-2026-106563 affects the following packages: @backstage/plugin-kubernetes-backend (npm). Ecosystems affected: npm.

How do I fix CVE-2026-106563?

Update @backstage/plugin-kubernetes-backend to 0.21.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-106563 is resolved across your whole dependency graph.

How do I detect CVE-2026-106563 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @backstage/plugin-kubernetes-backend, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-106563 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-106563 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-106563 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-106563?

CVE-2026-106563 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 12th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-106563?

CVE-2026-106563 is classified as Improper Input Validation (CWE-20), CWE-862 (CWE-862). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-106563 published, and has it been updated?

CVE-2026-106563 was published on October 7, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

CVE-2026-106563 — @backstage/plugin-kuberne…

MEDIUMFix: backstage/backstage@2d5d3e7

CVE-2026-106563 is a medium-severity (CVSS 5.3) Improper Input Validation vulnerability in @backstage/plugin-kubernetes-backend. A fix is available for @backstage/plugin-kubernetes-backend — see the affected versions and patch details below.

Backstage: Improper entity validation in deprecated Kubernetes services endpoint

Also known asGHSA-r9ph-3637-55px

Published

Oct 7, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-106563.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs12th percentile — riskier than 12% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-106563 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

📦@backstage/plugin-kubernetes-backend

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

Impact

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.

Patches

Patched in @backstage/plugin-kubernetes-backend version 0.21.8.

Workarounds

Disable the deprecated /services/:serviceId route by deploying a custom Kubernetes router that omits it.
Restrict access to the kubernetes.resources.read permission to limit the set of users who can reach the endpoint.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@backstage/plugin-kubernetes-backend`	all versions	0.21.8`npm install @backstage/plugin-kubernetes-backend@0.21.8`

Affected Products

2 products · 2 configurations

Application

backstagelinuxfoundation

< 1.54.1

range

Application

backstage\/plugin-kubernetes-backendlinuxfoundation

< 0.21.8

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @backstage/plugin-kubernetes-backend, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @backstage/plugin-kubernetes-backend to 0.21.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-106563 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### Impact 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. ### Patches Patched in `@backstage/plugin-kubernetes-backend` version 0.21.8. ### Workarounds - Disable the deprecated `/services/:serviceId` route by deploying a custom Kubernetes router that omits it. - Restrict access to the `kubernetes.resources.read` permission to limit the set of user