CVE-2026-40303

high

Description

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.

References

https://github.com/openziti/zrok/security/advisories/GHSA-cpf9-ph2j-ccr9

https://github.com/openziti/zrok/releases/tag/v2.0.1

Details

Source: Mitre, NVD

Published: 2026-04-17

Updated: 2026-04-23

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

EPSS

EPSS: 0.00057