CVE-2026-49991

high

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.

References

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

Details

Source: Mitre, NVD

Published: 2026-06-26

Updated: 2026-06-26

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N

Severity: High

CVSS v3

Base Score: 8.6

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Severity: High

EPSS

EPSS: 0.00069