CVE-2026-49991

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

State: Published
Severity: 8.6 High
Published: Jun 26, 2026
Updated: Jun 29, 2026
Reserved: Jun 2, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	8.6 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N	GitHub_M

Weaknesses

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-862 Missing Authorization

Affected Products

Product	Versions
rustfsrustfs	1.0.0-beta.4Affected

References

https://github.com/rustfs/rustfs/security/advisories/GHSA-f4vq-9ffr-m8m3

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