openziti zrok up to 2.0.0 endpoints.GetSessionCookie resource consumption

Summaryinfo

A vulnerability, which was classified as problematic, was found in openziti zrok up to 2.0.0. The affected element is the function endpoints.GetSessionCookie. The manipulation results in resource consumption. This vulnerability is reported as CVE-2026-40303. The attack can be launched remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in openziti zrok up to 2.0.0. Affected is the function endpoints.GetSessionCookie. The manipulation with an unknown input leads to a resource consumption vulnerability. CWE is classifying the issue as CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. This is going to have an impact on availability. CVE summarizes:

zrok is software for sharing web services, files, and network resources. Prior to version 2.0.1, endpoints.GetSessionCookie parses an attacker-supplied cookie chunk count and calls make([]string, count) with no upper bound before any token validation occurs. The function is reached on every request to an OAuth-protected proxy share, allowing an unauthenticated remote attacker to trigger gigabyte-scale heap allocations per request, leading to process-level OOM termination or repeated goroutine panics. Both publicProxy and dynamicProxy are affected. Version 2.0.1 patches the issue.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-40303 since 04/10/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 2.0.1 eliminates this vulnerability. The upgrade is hosted for download at github.com.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• openziti

Name

• zrok

Version

• 2.0

Website

• Product: https://github.com/openziti/zrok/

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CPE 2.2info

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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