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TI-2026-29081 Aliases CVE-2026-40303GHSA-cpf9-ph2j-ccr9

zrok allows unauthenticated DoS via unbounded memory allocation in striped session cookie parsing

Priority LOW 39CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00453 39th percentileScored 2026-11-07
Fix Fixed zrok (openziti): 2.0.1github.com/openziti/zrok/v2 (Go): 2.0.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
openzitizrokbefore 2.0.12.0.1Patch availableCNA
—github.com/openziti/zrok (Go)up to 1.1.11—No fix listedGHSA-cpf9-ph2j-ccr9
—github.com/openziti/zrok/v2 (Go)before 2.0.12.0.1Patch availableGHSA-cpf9-ph2j-ccr9
  • zrok Vendoropenziti Affected before 2.0.1 Fixed in 2.0.1 Patch available CNA
  • github.com/openziti/zrok (Go) Vendor— Affected up to 1.1.11 Fixed in — No fix listed GHSA-cpf9-ph2j-ccr9
  • github.com/openziti/zrok/v2 (Go) Vendor— Affected before 2.0.1 Fixed in 2.0.1 Patch available GHSA-cpf9-ph2j-ccr9

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:netfoundry:zrok:*:*:*:*:*:*:*:*before 2.0.1VulnerableNetfoundry
  • cpe:2.3:a:netfoundry:zrok:*:*:*:*:*:*:*:* Versions before 2.0.1 Vulnerable ·Netfoundry

Remediation

  • Fix · CNA zrok (openziti) Fixed in 2.0.1
  • Fix · GHSA-cpf9-ph2j-ccr9 github.com/openziti/zrok/v2 (Go) Fixed in 2.0.1 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-40303
  2. 2026-10-03 Alias added: GHSA-cpf9-ph2j-ccr9
  3. 2026-10-25 Priority changed: MEDIUM → LOW

References

Advisory 2

Other 2

  • TI-2026-33317 zrok Python ProxyShare can be used as an SSRF proxy through absolute URL paths CVSS 4.0CRITICAL 9.9
  • TI-2025-20335 Cross Site Scripting potential in Ziti Console CVSS 3.1HIGH 8.2
  • TI-2026-41883 OpenZiti - Privilege Escalation to Admin via Unauthorized Enrollment Creation CVSS 4.0HIGH 8.7
  • TI-2026-30586 zrok: WebDAV drive backend follows symlinks outside DriveRoot, enabling host filesystem read/write CVSS 3.1HIGH 8.7
  • TI-2026-33325 zrok copy writes attacker-controlled WebDAV paths outside the destination root CVSS 4.0HIGH 8.3
  • TI-2025-20336 Server Side Request Forgery in Ziti Console CVSS 3.1HIGH 8.6
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences