# CVE-2026-17107: Cluster-proxy: impersonation-header injection grants cluster-admin on every managed cluster

> An authenticated user can inject headers to gain cluster-admin privileges on all managed clusters in Red Hat Advanced Cluster Management.

- **Severity:** High 8.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Jul 2026
- **Updated:** 29 Sep 2026
- **Also known as:** GHSA-vr7g-637m-v9mm

## What is CVE-2026-17107?

CVE-2026-17107 is a high-severity vulnerability in Red Hat multicluster engine for Kubernetes 2.10, published on 24 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw was found in the cluster-proxy service-proxy component used in Red Hat Advanced Cluster Management for Kubernetes (RHACM) and multicluster-engine (MCE). The service-proxy appends impersonation group headers to proxied requests without first removing caller-supplied values, and the spoke ServiceAccount holds unrestricted impersonation permissions. An authenticated hub principal can inject an Impersonate-Group header to escalate to cluster-admin on every managed cluster.

Weakness: CWE-441 (Unintended Proxy or Intermediary)

## Which versions are affected by CVE-2026-17107?


## How do I fix CVE-2026-17107?

No fix has been published for CVE-2026-17107 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-17107 being exploited?

There is no known exploitation of CVE-2026-17107 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-17107 and fix it if it is affected.

What it is: CVE-2026-17107 is a high-severity vulnerability in Red Hat multicluster engine for Kubernetes 2.10, published on 24 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-17107 in the wild and no public exploit code.

Affected product: Red Hat multicluster engine for Kubernetes 2.10. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-17107/ (Markdown: https://insights.sbomify.com/CVE-2026-17107/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-17107
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-17107
- OSV: https://osv.dev/vulnerability/CVE-2026-17107

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-17107/
Summaries are generated and may contain mistakes; the official description above is the record.