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Medium

CoreWCF NetNamedPipe transport accepts attach to a pre-existing named pipe instance

Type: advisorySources: OSV

CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF NetNamedPipe transport accepts attachment to a pre-existing named pipe instance, allowing local interception of NetNamedPipe traffic when an attacker races NamedPipeListener startup between shared memory GUID publication and service named pipe creation. This issue is fixed in versions 1.8.1 and 1.9.1.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-54777
Confirmed fixed CVEs
Not specified
Updated in this feed
2 Nov 2026, 17:21 UTC · Revision 1

Source evidence

CoreWCF NetNamedPipe transport accepts attach to a pre-existing named pipe instance

core-osv · Original source

Published 8 Jul 2026, 22:01 UTC

CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF NetNamedPipe transport accepts attachment to a pre-existing named pipe instance, allowing local interception of NetNamedPipe traffic when an attacker races NamedPipeListener startup between shared memory GUID publication and service named pipe creation. This issue is fixed in versions 1.8.1 and 1.9.1.

osv:CVE-2026-54777
Complete source record
{
  "id": "513faf3a26f5b0c67dff9f7fb46fc881a6ce24fd74909f842c63204863ed09e6",
  "url": "https://osv.dev/vulnerability/CVE-2026-54777",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CoreWCF NetNamedPipe transport accepts attach to a pre-existing named pipe instance",
    "summary": "CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, CoreWCF NetNamedPipe transport accepts attachment to a pre-existing named pipe instance, allowing local interception of NetNamedPipe traffic when an attacker races NamedPipeListener startup between shared memory GUID publication and service named pipe creation. This issue is fixed in versions 1.8.1 and 1.9.1.",
    "evidence": "osv:CVE-2026-54777",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-54777",
      "aliases": [
        "CVE-2026-54777",
        "GHSA-6jj2-4q5c-x8g6"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/corewcf/corewcf",
              "type": "GIT",
              "events": [
                {
                  "introduced": "39b2f02978e497955a560c72b5ccdff5c0dbcda1"
                },
                {
                  "fixed": "1f7a0811da5128db40fd7b868ae0aac0c581f91f"
                },
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7c0920fe16adc497efae82881ac0f1e4d7ac98d0"
                },
                {
                  "fixed": "8ed9c780c7c6fb22fa215c5771dee0c1e49596b7"
                },
                {
                  "fixed": "e7d225394fd429900dcbc445dcdd53b94e964077"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.9.0"
                      },
                      {
                        "fixed": "1.9.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.8.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8ed9c780c7c6fb22fa215c5771dee0c1e49596b7"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "e7d225394fd429900dcbc445dcdd53b94e964077"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "7c0920fe16adc497efae82881ac0f1e4d7ac98d0"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.8.1"
                  },
                  {
                    "range": [
                      {
                        "fixed": "1f7a0811da5128db40fd7b868ae0aac0c581f91f"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.9.1"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.8.0",
            "v1.9.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54777.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:21.375906714Z",
      "provider": "osv",
      "references": [
        "https://github.com/CoreWCF/CoreWCF/releases/tag/v1.8.1",
        "https://github.com/CoreWCF/CoreWCF/releases/tag/v1.9.1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54777.json",
        "https://github.com/CoreWCF/CoreWCF/security/advisories/GHSA-6jj2-4q5c-x8g6",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-54777",
        "https://github.com/CoreWCF/CoreWCF/commit/8ed9c780c7c6fb22fa215c5771dee0c1e49596b7",
        "https://github.com/CoreWCF/CoreWCF/commit/e7d225394fd429900dcbc445dcdd53b94e964077"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-367",
          "CWE-665"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54777.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-54777",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 487704,
  "published_at": "2026-07-08T22:01:21.323+00:00"
}