CVE-2026-40304Network attack vector

Service interruption via null ownership guard

Published Apr 17, 2026 · Updated Apr 17, 2026

Incorrect authorization in OpenZiti zrok before 2.0.1 allows remote authenticated users to delete a global frontend via the unaccess API. The unaccessHandler.Handle ownership guard treats a NULL frontend environment_id as a reason to skip ownership verification, then deletes the record. Exploitation requires a valid account, an owned environment ID, and knowledge of a global frontend token; deletion interrupts every public share routed through that frontend.

CVSS severity5.3
Medium
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

Incorrect authorization in OpenZiti zrok before 2.0.1 allows remote authenticated users to delete a global frontend via the unaccess API. The unaccessHandler.Handle ownership guard treats a NULL frontend environment_id as a reason to skip ownership verification, then deletes the record. Exploitation requires a valid account, an owned environment ID, and knowledge of a global frontend token; deletion interrupts every public share routed through that frontend.

The record

CVE
CVE-2026-40304
Published
Apr 17, 2026
Updated
Apr 17, 2026
Vendor
OpenZiti
Product
zrok
Classifications
CWE-863, CWE-284, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 17, 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=< 2.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenZiti · zrokversion=< 2.0.1

Published CVSS scores

5.3GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

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-863Incorrect Authorization
CWE-284Improper Access Control
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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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