{"cve":"CVE-2026-49991","nvd":{"published":"2026-06-26T20:17:17.817","modified":"2026-06-29T14:16:55.580","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","score":8.6},"cwes":["CWE-22","CWE-862"],"references":["https://github.com/rustfs/rustfs/security/advisories/GHSA-f4vq-9ffr-m8m3","https://github.com/rustfs/rustfs/security/advisories/GHSA-f4vq-9ffr-m8m3"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:41:17.107060303+00:00"},"epss":{"cve":"CVE-2026-49991","score":0.00415,"percentile":0.35823,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}