Vulnerability · Published Feb 3, 2026 · Assigned by GitHub_M

CVE-2026-21862RustFS sourceIp bypass via spoofed X-Forwarded-For/Real-IP headers

High 7.7

In plain English

A high-severity authentication bypass by spoofing in rustfs from rustfs. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities).

Severity (CVSS 4.0)7.7High

Exploit odds (30 days)0.3%top 83.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
rustfs	rustfs	< alpha.78

Weakness: CWE-290 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

References

https://github.com/rustfs/rustfs/security/advisories/GHSA-fc6g-2gcp-2qrq x_refsource_CONFIRM