{"cve":"CVE-2026-40303","nvd":{"published":"2026-04-17T21:16:35.140","modified":"2026-10-26T22:10:00.163","status":"Analyzed","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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400","CWE-789"],"references":["https://github.com/openziti/zrok/releases/tag/v2.0.1","https://github.com/openziti/zrok/security/advisories/GHSA-cpf9-ph2j-ccr9"],"products":["netfoundry:zrok"],"source":"nvd","synced_at":"2026-10-26T22:26:44.656832877+00:00"},"epss":{"cve":"CVE-2026-40303","score":0.00453,"percentile":0.39068,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-cpf9-ph2j-ccr9","url":"https://osv.dev/vulnerability/GHSA-cpf9-ph2j-ccr9","summary":"zrok: Unauthenticated DoS via unbounded memory allocation in striped session cookie parsing","modified":"2026-06-25T19:56:15.928294968Z","packages":[{"ecosystem":"Go","name":"github.com/openziti/zrok","purl":"pkg:golang/github.com/openziti/zrok","ranges":["<=1.1.11"],"fixed":[]},{"ecosystem":"Go","name":"github.com/openziti/zrok/v2","purl":"pkg:golang/github.com/openziti/zrok/v2","ranges":["<2.0.1"],"fixed":["2.0.1"]}]},{"id":"GO-2026-5329","url":"https://osv.dev/vulnerability/GO-2026-5329","summary":"zrok: Unauthenticated DoS via unbounded memory allocation in striped session cookie parsing in github.com/openziti/zrok","modified":"2026-06-25T19:45:30.551551058Z","packages":[{"ecosystem":"Go","name":"github.com/openziti/zrok","purl":"pkg:golang/github.com/openziti/zrok","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/openziti/zrok/v2","purl":"pkg:golang/github.com/openziti/zrok/v2","ranges":["<2.0.1"],"fixed":["2.0.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}