Read the docs
TI-2026-36822 Aliases CVE-2026-49991

RustFS Snowball Auto-Extract: Path Traversal allows cross-bucket object injection

Priority HIGH 76CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · 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. In 1.0.0-beta.4, authenticated users with only PutObject permission on their own bucket can exploit a path traversal vulnerability in the Snowball auto-extract feature to write arbitrary objects into other users' buckets, completely breaking multi-tenant isolation. The vulnerability chains three flaws: No ../ sanitization in tar entry key normalization; IAM wildcard matching uses raw (uncleaned) paths; and Filesystem path cleaning resolves ../ across bucket boundaries.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00415 36th 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
Yes
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-beta.4—No fix listedCNA
  • rustfs Vendorrustfs Affected 1.0.0-beta.4 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-2026-49991

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-2026-32894 RustFS: ImportIam Allows Creation of Backdoor Service Accounts Under Any Parent Including Root CVSS 4.0CRITICAL 9.3
  • TI-2026-17564 RustFS sourceIp bypass via spoofed X-Forwarded-For/Real-IP headers CVSS 4.0HIGH 7.7
See all 32 →

Sources

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