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.

Project Subscriptions

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-cpf9-ph2j-ccr9 zrok: Unauthenticated DoS via unbounded memory allocation in striped session cookie parsing
Fixes

Solution

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Workaround

No workaround given by the vendor.

History

Fri, 17 Apr 2026 21:15:00 +0000

Type Values Removed Values Added
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.
Title zrok allows unauthenticated DoS via unbounded memory allocation in striped session cookie parsing
Weaknesses CWE-400
CWE-789
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-17T21:01:51.899Z

Reserved: 2026-04-10T20:22:44.036Z

Link: CVE-2026-40303

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-04-17T21:16:35.140

Modified: 2026-04-17T21:16:35.140

Link: CVE-2026-40303

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses