Auth bypass in Rustfs

CVE-2026-22042

RustFS is a distributed object storage system built in Rust. Prior to version 1.0.0-alpha.79, he `ImportIam` admin API validates permissions using `ExportIAMAction` instead of `ImportIAMAction`, allowing a principal with export-only IAM permissions to perform import operations. Since importing IAM data performs privileged write actions (creating/updating users, groups, policies, and service accounts), this can lead to unauthorized IAM modification and privilege escalation. Version 1.0.0-alpha.79 fixes the issue.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-22042: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

  • Rustfs — versions 1.0.0, < 1.0.0-alpha.79

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-22042?
CVE-2026-22042 is a high-severity vulnerability in Rustfs, classified under Improper Authorization. CVSS score: 8.8/10. Published 2026-01-08.
How severe is CVE-2026-22042?
High severity. CVSS v3 base score is 8.8 out of 10.