Medium severity · published Jun 26, 2026
CVE-2026-55838
RustFS: Missing admin authorization on /rustfs/admin/v3/metrics allows any authenticated user to read server metrics
4.3
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 19% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RU
rustfs · rustfs
<= 1.0.0-beta.7 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-55838
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-55838
github.com
https://github.com/rustfs/rustfs/security/advisories/GHSA-f5cv-v44x-2xgf
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