Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Netfoundry | Zrok | < 2.0.1 |
Related Weaknesses (CWE)
References
- https://github.com/openziti/zrok/releases/tag/v2.0.1Release Notes
- https://github.com/openziti/zrok/security/advisories/GHSA-cpf9-ph2j-ccr9Vendor Advisory
FAQ
What is CVE-2026-40303?
CVE-2026-40303 is a vulnerability with a CVSS score of 7.5 (HIGH). 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, coun...
How severe is CVE-2026-40303?
CVE-2026-40303 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40303?
Check the references section above for vendor advisories and patch information. Affected products include: Netfoundry Zrok.