{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "echo",
          "vendor": "labstack",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 4.0.0, \u003c 4.16.1"
            },
            {
              "status": "affected",
              "version": "\u003e= 5.0.0, \u003c 5.4.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Echo is a Go web framework. From 4.0.0 until 4.16.1 and 5.4.1, Echo\u0027s 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\u0027s 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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "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",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-863",
              "description": "CWE-863: Incorrect Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-28T19:03:01.533Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "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"
        }
      ],
      "source": {
        "advisory": "GHSA-cxf3-9h37-7rr8",
        "discovery": "UNKNOWN"
      },
      "title": "Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-118264",
    "datePublished": "2026-10-28T19:03:01.533Z",
    "dateReserved": "2026-10-27T20:13:55.314Z",
    "dateUpdated": "2026-10-28T19:03:01.533Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}