Envoy forwards early CONNECT data in TCP proxy mode_CVE-2025-64763

{
    "lastseen": "",
    "description": "Envoy is a high-performance edge/middle/service proxy. In 1.33.12, 1.34.10, 1.35.6, 1.36.2, and earlier, when Envoy is configured in TCP proxy mode to handle CONNECT requests, it accepts client data before issuing a 2xx response and forwards that data to the upstream TCP connection. If a forwarding proxy upstream from Envoy then responds with a non-2xx status, this can cause a de-synchronized CONNECT tunnel state. By default Envoy continues to allow early CONNECT data to avoid disrupting existing deployments. The envoy.reloadable_features.reject_early_connect_data runtime flag can be set to reject CONNECT requests that send data before a 2xx response when intermediaries upstream from Envoy may reject establishment of a CONNECT tunnel.",
    "published": "2025-12-03T18:13:58.496Z",
    "modified": "2025-12-03T20:02:40.284Z",
    "type": "cve",
    "title": "Envoy forwards early CONNECT data in TCP proxy mode",
    "source": "GitHub_M",
    "references": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-rj35-4m94-77jh",
    "id": "CVE-2025-64763",
    "bulletinFamily": "",
    "cwe": [
        "CWE-693"
    ],
    "cvelist": null,
    "sourceData": "envoyproxy envoy >= 1.36.0, <= 1.36.2\nenvoyproxy envoy >= 1.35.0, <= 1.35.6\nenvoyproxy envoy >= 1.34.0, <= 1.34.10\nenvoyproxy envoy <= 1.33.12",
    "sourceHref": "",
    "cvss": {
        "score": 3.7,
        "severity": "LOW",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
        "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": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "envoy",
    "version": ">= 1.36.0, <= 1.36.2",
    "vendor": "envoyproxy",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}