What is CVE-2026-21862?

CVE-2026-21862 is a high-severity vulnerability in Rustfs, classified under Authentication Bypass by Spoofing. CVSS score: 7.5/10. Published 2026-02-03.

How severe is CVE-2026-21862?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Rustfs

CVE-2026-21862

RustFS is a distributed object storage system built in Rust. Prior to version alpha.78, IP-based access control can be bypassed: get_condition_values trusts client-supplied X-Forwarded-For/X-Real-Ip without verifying a trusted proxy, so any reachable client can spoof aws:SourceIp and satisfy IP-allowlist policies. This issue has been patched in version alpha.78.

EPSS: 0.002 (11.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Rustfs — versions 1.0.0, < alpha.78

Weakness classification (CWE)

CWE-290 — Authentication Bypass by Spoofing

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-21862?: CVE-2026-21862 is a high-severity vulnerability in Rustfs, classified under Authentication Bypass by Spoofing. CVSS score: 7.5/10. Published 2026-02-03.
How severe is CVE-2026-21862?: High severity. CVSS v3 base score is 7.5 out of 10.