{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-118264",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-10-27T20:13:55.314Z",
        "datePublished": "2026-10-28T19:03:01.533Z",
        "dateUpdated": "2026-10-28T19:03:01.533Z"
    },
    "containers": {
        "cna": {
            "title": "Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-444",
                            "lang": "en",
                            "description": "CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-863",
                            "lang": "en",
                            "description": "CWE-863: Incorrect Authorization",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 9.1,
                        "baseSeverity": "CRITICAL",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/labstack/echo/security/advisories/GHSA-cxf3-9h37-7rr8",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/labstack/echo/security/advisories/GHSA-cxf3-9h37-7rr8"
                },
                {
                    "name": "https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec"
                },
                {
                    "name": "https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f"
                },
                {
                    "name": "https://github.com/labstack/echo/releases/tag/v4.16.1",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/labstack/echo/releases/tag/v4.16.1"
                },
                {
                    "name": "https://github.com/labstack/echo/releases/tag/v5.4.1",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/labstack/echo/releases/tag/v5.4.1"
                }
            ],
            "affected": [
                {
                    "vendor": "labstack",
                    "product": "echo",
                    "versions": [
                        {
                            "version": ">= 4.0.0, < 4.16.1",
                            "status": "affected"
                        },
                        {
                            "version": ">= 5.0.0, < 5.4.1",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-10-28T19:03:01.533Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Echo is a Go web framework. From 4.0.0 until 4.16.1 and 5.4.1, Echo's Proxy middleware selects a raw tunnel from a client WebSocket upgrade request before verifying that the configured upstream accepted the upgrade. If the upstream rejects the upgrade with an ordinary keep-alive response, later HTTP requests on the connection are sent directly to that upstream without passing through Echo's router or route-specific middleware. This can bypass authentication or authorization enforced only by Echo routes, but requires an accessible proxy route, a cooperating rejected-upgrade response, and a target without independent upstream authorization. This issue is fixed in 4.16.1 and 5.4.1."
                }
            ],
            "source": {
                "advisory": "GHSA-cxf3-9h37-7rr8",
                "discovery": "UNKNOWN"
            }
        }
    }
}