zrok allows unauthenticated DoS via unbounded memory allocation in striped session cookie parsing_CVE-2026-40303

{
    "lastseen": "",
    "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.",
    "published": "2026-04-17T21:01:51.899Z",
    "modified": "2026-04-17T21:01:51.899Z",
    "type": "cve",
    "title": "zrok allows unauthenticated DoS via unbounded memory allocation in striped session cookie parsing",
    "source": "GitHub_M",
    "references": "https://github.com/openziti/zrok/security/advisories/GHSA-cpf9-ph2j-ccr9\nhttps://github.com/openziti/zrok/releases/tag/v2.0.1",
    "id": "CVE-2026-40303",
    "bulletinFamily": "",
    "cwe": [
        "CWE-400",
        "CWE-789"
    ],
    "cvelist": null,
    "sourceData": "openziti zrok < 2.0.1",
    "sourceHref": "",
    "cvss": {
        "score": 7.5,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
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            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "zrok",
    "version": "< 2.0.1",
    "vendor": "openziti",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}