Envoy: Segmentation fault when using %REQUESTED_SERVER_NAME% in log format_CVE-2026-47220

{
    "lastseen": "",
    "description": "Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.37.0 until 1.37.5 and 1.38.3, when the %REQUESTED_SERVER_NAME(X:Y)% is used in log format and host related options is specified, like HOST_FIRST, SNI_FIRST, it's possible to crash Envoy when the specified host header is missing in the request headers. This vulnerability is fixed in 1.37.5 and 1.38.3.",
    "published": "2026-06-26T18:02:17.679Z",
    "modified": "2026-06-26T18:02:17.679Z",
    "type": "cve",
    "title": "Envoy: Segmentation fault when using %REQUESTED_SERVER_NAME% in log format",
    "source": "GitHub_M",
    "references": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-j9wh-4qfm-wf2v",
    "id": "CVE-2026-47220",
    "bulletinFamily": "",
    "cwe": [
        "CWE-476"
    ],
    "cvelist": null,
    "sourceData": "envoyproxy envoy >= 1.38.0, < 1.38.3\nenvoyproxy envoy >= 1.37.0, < 1.37.5",
    "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": "envoy",
    "version": ">= 1.38.0, < 1.38.3",
    "vendor": "envoyproxy",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}