{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "4.0.0"
                  },
                  {
                    "fixed": "4.16.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "introduced": "5.0.0"
                  },
                  {
                    "fixed": "5.4.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "fixed": "1855061e572ae9dab727c811d8382f266bfbaaec"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "range": [
                  {
                    "fixed": "3fb0ba7e17645bb65611e2a08875d0a2f65c421f"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "original_tag": "v4.16.1",
                "range": [
                  {
                    "fixed": "600b9855dfbcb22c7e643e43ce397d5248e882b2"
                  }
                ],
                "source": "REFERENCES_TAG"
              },
              {
                "original_tag": "v5.4.1",
                "range": [
                  {
                    "fixed": "a6a9673a54d2c719ceb32ce6a929d35483acfb2b"
                  }
                ],
                "source": "REFERENCES_TAG"
              }
            ]
          },
          "events": [
            {
              "introduced": "6d9e043284aea2d07f5fcaf0d3a424eb7d9f6109"
            },
            {
              "fixed": "600b9855dfbcb22c7e643e43ce397d5248e882b2"
            },
            {
              "introduced": "9500f2745481e2dff1313e2e6734c488e80c13fb"
            },
            {
              "fixed": "a6a9673a54d2c719ceb32ce6a929d35483acfb2b"
            },
            {
              "fixed": "1855061e572ae9dab727c811d8382f266bfbaaec"
            },
            {
              "fixed": "3fb0ba7e17645bb65611e2a08875d0a2f65c421f"
            }
          ],
          "repo": "https://github.com/labstack/echo",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-cxf3-9h37-7rr8"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-444",
      "CWE-863"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118264.json"
  },
  "details": "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.",
  "id": "CVE-2026-118264",
  "modified": "2026-10-29T10:30:23.538383205Z",
  "published": "2026-10-28T19:03:01.533Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118264.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/labstack/echo/commit/1855061e572ae9dab727c811d8382f266bfbaaec"
    },
    {
      "type": "FIX",
      "url": "https://github.com/labstack/echo/commit/3fb0ba7e17645bb65611e2a08875d0a2f65c421f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/labstack/echo/releases/tag/v4.16.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/labstack/echo/releases/tag/v5.4.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/labstack/echo/security/advisories/GHSA-cxf3-9h37-7rr8"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118264"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Echo: Rejected WebSocket upgrades can bypass Echo route-level access controls"
}