CVE-2026-40937Network attack vector

Event interception via missing admin authorization

Published Apr 22, 2026 · Updated Apr 22, 2026

Authorization bypass in RustFS before 1.0.0-alpha.94 allows remote authenticated users to redirect or delete notification targets. The four event-target handlers in rustfs/src/admin/handlers/event.rs authenticate access keys and session tokens but never call validate_admin_request for an AdminAction. A non-admin account can replace a shared target, redirect bucket-event metadata to an attacker-controlled endpoint, or delete targets to evade auditing.

CVSS severity8.3
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in RustFS before 1.0.0-alpha.94 allows remote authenticated users to redirect or delete notification targets. The four event-target handlers in rustfs/src/admin/handlers/event.rs authenticate access keys and session tokens but never call validate_admin_request for an AdminAction. A non-admin account can replace a shared target, redirect bucket-event metadata to an attacker-controlled endpoint, or delete targets to evade auditing.

The record

CVE
CVE-2026-40937
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
RustFS
Product
RustFS
Classifications
CWE-862, T1562.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 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-alpha.94

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

RustFS · RustFSversion=< 1.0.0-alpha.94

Published CVSS scores

8.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
T1562.001Impair Defenses: Disable or Modify Tools

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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