CVE-2026-40304: CWE-284: Improper Access Control in openziti zrok
zrok is software for sharing web services, files, and network resources. Prior to version 2.0.1, the unaccess handler (controller/unaccess.go) contains a logical error in its ownership guard: when a frontend record has environment_id = NULL (the marker for admin-created global frontends), the condition short-circuits to false and allows the deletion to proceed without any ownership verification. A non-admin user who knows a global frontend token can call DELETE /api/v2/unaccess with any of their own environment IDs and permanently delete the global frontend, taking down all public shares routed through it. Version 2.0.1 patches the issue.
AI Analysis
Technical Summary
The vulnerability in openziti zrok (CVE-2026-40304) involves a logical flaw in the unaccess handler's ownership guard. Specifically, when a frontend record has a NULL environment_id (indicating an admin-created global frontend), the check incorrectly short-circuits, allowing deletion without verifying ownership. Consequently, a non-admin user who knows a global frontend token can exploit this by calling DELETE /api/v2/unaccess with any of their own environment IDs, leading to permanent deletion of the global frontend and disruption of all public shares routed through it. This flaw affects versions prior to 2.0.1, which includes the fix.
Potential Impact
The vulnerability allows non-admin users to delete global frontend resources that they do not own, causing denial of service by taking down all public shares routed through the deleted frontend. There is no direct confidentiality or integrity impact reported, but availability is significantly affected.
Mitigation Recommendations
Upgrade to openziti zrok version 2.0.1 or later, which patches the improper access control vulnerability. Since the vendor has released a fixed version, applying this official update is the recommended remediation. Patch status is confirmed by the versioning information in the advisory.
CVE-2026-40304: CWE-284: Improper Access Control in openziti zrok
Description
zrok is software for sharing web services, files, and network resources. Prior to version 2.0.1, the unaccess handler (controller/unaccess.go) contains a logical error in its ownership guard: when a frontend record has environment_id = NULL (the marker for admin-created global frontends), the condition short-circuits to false and allows the deletion to proceed without any ownership verification. A non-admin user who knows a global frontend token can call DELETE /api/v2/unaccess with any of their own environment IDs and permanently delete the global frontend, taking down all public shares routed through it. Version 2.0.1 patches the issue.
CVSS v3.1
Score 5.3medium
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in openziti zrok (CVE-2026-40304) involves a logical flaw in the unaccess handler's ownership guard. Specifically, when a frontend record has a NULL environment_id (indicating an admin-created global frontend), the check incorrectly short-circuits, allowing deletion without verifying ownership. Consequently, a non-admin user who knows a global frontend token can exploit this by calling DELETE /api/v2/unaccess with any of their own environment IDs, leading to permanent deletion of the global frontend and disruption of all public shares routed through it. This flaw affects versions prior to 2.0.1, which includes the fix.
Potential Impact
The vulnerability allows non-admin users to delete global frontend resources that they do not own, causing denial of service by taking down all public shares routed through the deleted frontend. There is no direct confidentiality or integrity impact reported, but availability is significantly affected.
Mitigation Recommendations
Upgrade to openziti zrok version 2.0.1 or later, which patches the improper access control vulnerability. Since the vendor has released a fixed version, applying this official update is the recommended remediation. Patch status is confirmed by the versioning information in the advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-10T21:41:54.504Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e2a83ebdfbbecc5994f134
Added to database: 4/17/2026, 9:38:06 PM
Last enriched: 4/25/2026, 2:56:17 AM
Last updated: 6/1/2026, 8:33:06 PM
Views: 47
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