# CVE-2026-55838: RustFS: Missing admin authorization on /rustfs/admin/v3/metrics allows any authenticated user to read server metrics

> An authenticated user can read sensitive server-wide operational metrics due to missing admin authorization checks on the metrics endpoint.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **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:** 26 Jun 2026
- **Updated:** 27 Jun 2026
- **Also known as:** GHSA-f5cv-v44x-2xgf

## What is CVE-2026-55838?

CVE-2026-55838 is a medium-severity missing authorization vulnerability in rustfs, published on 26 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

RustFS is a distributed object storage system built in Rust. In 1.0.0-beta.7 and earlier, the real-time metrics endpoint at /rustfs/admin/v3/metrics is accessible to any valid IAM user regardless of their assigned policy. Every other admin handler in the codebase calls validate_admin_request to enforce admin-action IAM checks; the MetricsHandler skips this call entirely. A restricted IAM user whose policy grants only access to their own bucket can read server-wide operational metrics including disk I/O statistics, network throughput, scanner cycle timing, and cluster RPC state.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-55838?


## How do I fix CVE-2026-55838?

No fix has been published for CVE-2026-55838 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-55838 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55838 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55838 and fix it if it is affected.

What it is: CVE-2026-55838 is a medium-severity missing authorization vulnerability in rustfs, published on 26 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55838 exists.

Affected product: rustfs. 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-2026-55838/ (Markdown: https://insights.sbomify.com/CVE-2026-55838/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55838
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55838
- OSV: https://osv.dev/vulnerability/CVE-2026-55838

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-55838/
Summaries are generated and may contain mistakes; the official description above is the record.