CVE-2026-49991Public exploitNetwork attack vectorHinoki check available

Cross-bucket object writes via Snowball path traversal

Published Jun 26, 2026 · Updated Jun 26, 2026

Path traversal in RustFS 1.0.0-alpha.1 through 1.0.0-beta.8 allows remote authenticated users to write objects across buckets. Snowball extraction preserves parent-directory segments, IAM matches the raw object key, and filesystem cleaning resolves the segments beyond the source bucket. PutObject permission on one bucket is sufficient, and Snowball auto-extract is enabled by default; successful exploitation injects or overwrites another tenant's objects.

CVSS severity8.6
High
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Path traversal in RustFS 1.0.0-alpha.1 through 1.0.0-beta.8 allows remote authenticated users to write objects across buckets. Snowball extraction preserves parent-directory segments, IAM matches the raw object key, and filesystem cleaning resolves the segments beyond the source bucket. PutObject permission on one bucket is sufficient, and Snowball auto-extract is enabled by default; successful exploitation injects or overwrites another tenant's objects.

The record

CVE
CVE-2026-49991
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
RustFS
Product
RustFS
Classifications
CWE-862, CWE-22, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.0-beta.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

RustFS · RustFSversion=1.0.0-beta.4

Published CVSS scores

8.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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