{"id":"CVE-2026-40303","sourceIdentifier":"security-advisories@github.com","published":"2026-04-17T21:16:35.140","lastModified":"2026-06-17T10:44:58.260","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"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":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"openziti","product":"zrok","versions":[{"version":"< 2.0.1","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-04-20T16:18:59.334800Z","id":"CVE-2026-40303","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-400"},{"lang":"en","value":"CWE-789"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:netfoundry:zrok:*:*:*:*:*:*:*:*","versionEndExcluding":"2.0.1","matchCriteriaId":"70C6F018-6D34-4A75-A49D-A795B0A5B056"}]}]}],"references":[{"url":"https://github.com/openziti/zrok/releases/tag/v2.0.1","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/openziti/zrok/security/advisories/GHSA-cpf9-ph2j-ccr9","source":"security-advisories@github.com","tags":["Vendor Advisory"]}]}