{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:golang:crypto:*:*:*:*:*:go:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "0.56.0"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "86efde54dc7069251a8b007026c500d28e4239ce"
            }
          ],
          "repo": "https://github.com/golang/crypto",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Go",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56855.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "fixed": "0.56.0"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking.",
  "id": "CVE-2026-56855",
  "modified": "2026-09-06T03:30:42.683674480Z",
  "published": "2026-09-02T19:37:05.807Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://go.dev/cl/826524"
    },
    {
      "type": "WEB",
      "url": "https://go.dev/issue/81317"
    },
    {
      "type": "WEB",
      "url": "https://groups.google.com/g/golang-announce/c/1y3fb2np35U"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev"
    },
    {
      "type": "WEB",
      "url": "https://pkg.go.dev/vuln/GO-2026-6355"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56855.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56855"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Prevent DoS on deadlocked established channel in golang.org/x/crypto/ssh"
}