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OpenAdvisories
High · 7.5 CVE-2026-40303 EUVD-2026-23550GHSA-cpf9-ph2j-ccr9GO-2026-5329

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

Published Apr 17, 2026 · Updated Apr 20, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
openziti zrok < 2.0.1 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/openziti/zrok <= 1.1.11 — GHSA-cpf9-ph2j-ccr9
Go github.com/openziti/zrok all versions — GO-2026-5329
Go github.com/openziti/zrok/v2 < 2.0.1 2.0.1 GHSA-cpf9-ph2j-ccr9

Advisories 1

References