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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
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
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.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-55838 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55838 exists.
Sources
Also known as GHSA-f5cv-v44x-2xgf.