Read the docs
TI-2026-39870 Aliases CVE-2026-55189

RustFS: FTP frontend skips IAM authorization on object reads

Priority HIGH 67CWE-862Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-862.

Summary

RustFS is a distributed object storage system built in Rust. From 1.0.0-alpha.1 until 1.0.0-beta.9, when the FTP frontend is enabled, the FTP read and probe handlers dispatch directly to the storage backend without ever calling the IAM authorization function that the FTP write/list handlers (and the entire HTTP S3 path) use. As a result, any user who can authenticate to the FTP listener — including a user whose IAM policy contains an explicit Deny on s3:GetObject — can read (RETR) and stat (SIZE/MDTM) any object in any bucket, and probe any bucket (CWD), completely regardless of their IAM policy. This vulnerability is fixed in 1.0.0-beta.9.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.0034 27th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
rustfsrustfs1.0.0-alpha.1 – 1.0.0-beta.8—No fix listedCNA
  • rustfs Vendorrustfs Affected 1.0.0-alpha.1 – 1.0.0-beta.8 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:rustfs:rustfs:*:*:*:*:*:*:*:*——rustfs
  • cpe:2.3:a:rustfs:rustfs:*:*:*:*:*:*:*:* Versions — — ·rustfs

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-55189

References

Other 1

  • TI-2025-42382 RustFS has a gRPC Hardcoded Token Authentication Bypass CVSS 3.1CRITICAL 9.8
  • TI-2026-32895 RustFS: Authentication bypass in /profile/cpu and /profile/memory allows unauthenticated access to profiling handlers CVSS 4.0HIGH 8.8
  • TI-2026-32892 RustFS: Hard-coded RSA private key in license verifier permits arbitrary license forgery CVSS 4.0HIGH 8.7
  • TI-2025-42176 RustFS Path Traversal Vulnerability CVSS 4.0HIGH 8.8
  • TI-2026-36822 RustFS Snowball Auto-Extract: Path Traversal allows cross-bucket object injection CVSS 3.1HIGH 8.6
  • TI-2026-32894 RustFS: ImportIam Allows Creation of Backdoor Service Accounts Under Any Parent Including Root CVSS 4.0CRITICAL 9.3
See all 32 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences