CVE-2026-40304 zrok's broken ownership check in DELETE /api/v2/unaccess allows non-admin to delete global frontend records
A non-admin user can delete global frontend records in zrok, disrupting public shares, due to a broken ownership check.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40304?
CVE-2026-40304 is a medium-severity missing authorization vulnerability in openziti zrok, published on 17 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-40304?
6 open source packages ship an affected version, including github.com/openziti/zrok and github.com/openziti/zrok/v2. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/openziti/zrok Go | All versions | None |
github.com/openziti/zrok Go | All versions to 1.1.11 | None |
github.com/openziti/zrok Go | All versions to 1.1.11 | None |
github.com/openziti/zrok/v2 Go | All versions | 2.0.1 |
github.com/openziti/zrok/v2 Go | All versions | 2.0.1 |
github.com/openziti/zrok/v2 Go | All versions | 2.0.1 |
Products include Netfoundry Zrok.
How do I fix CVE-2026-40304?
Upgrade to a fixed version.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-40304 being exploited?
There is no known exploitation of CVE-2026-40304 in the wild and no public exploit code.
Other vulnerabilities in openziti zrok
- CVE-2026-45568 zrok Python ProxyShare can be used as an SSRF proxy through absolute URL paths
- CVE-2026-42275 zrok: WebDAV drive backend follows symlinks outside DriveRoot, enabling host filesystem read/write
- CVE-2026-45576 zrok copy writes attacker-controlled WebDAV paths outside the destination root
- CVE-2026-40303 zrok allows unauthenticated DoS via unbounded memory allocation in striped session cookie parsing
- CVE-2026-40302 zrok has reflected XSS in GitHub OAuth callback via unsanitized refreshInterval error rendering
Sources
Also known as GHSA-3jpj-v3xr-5h6g, GO-2026-5090.