Vulnerability · Published Jun 26, 2026 · Assigned by GitHub_M

CVE-2026-49991RustFS Snowball Auto-Extract: Path Traversal allows cross-bucket object injection

High 8.6

In plain English

A high-severity path traversal in rustfs from rustfs. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).

Severity (CVSS 3.1)8.6High

Exploit odds (30 days)0.4%top 64.0% 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. 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.

Affected products (as reported)

Vendor	Product	Versions
rustfs	rustfs	1.0.0-beta.4

Weakness: CWE-22, CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

References

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