{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55640",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-25T18:38:39.313226Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-25T19:20:43.689Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "nextcloud-mcp-server",
          "vendor": "cbcoutinho",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.117.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Nextcloud MCP Server is a production-ready MCP server that connects AI assistants to a Nextcloud instance. Prior to 0.117.2, the POST /webhooks/nextcloud endpoint in nextcloud_mcp_server/vector/webhook_receiver.py has no authentication by default because WEBHOOK_SECRET defaults to None and startup validation does not require it. When WEBHOOK_SECRET is unset, handle_nextcloud_webhook() accepts unauthenticated requests. The payload[\"user\"][\"uid\"] field parsed in nextcloud_mcp_server/vector/webhook_parser.py is attacker-controlled and is used without an authenticated-session cross-check for Qdrant operations, allowing a network attacker to delete or trigger re-indexing of vector embeddings for any user and to destroy the semantic search index by sending forged deletion events. This issue is fixed in version 0.117.2."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-306",
              "description": "CWE-306: Missing Authentication for Critical Function",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-25T16:03:28.085Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/cbcoutinho/nextcloud-mcp-server/security/advisories/GHSA-8vh3-g2qg-2h2c",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/cbcoutinho/nextcloud-mcp-server/security/advisories/GHSA-8vh3-g2qg-2h2c"
        },
        {
          "name": "https://github.com/cbcoutinho/nextcloud-mcp-server/commit/4fc2b10945108cf1008ec9698291de6706ffcb73",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/cbcoutinho/nextcloud-mcp-server/commit/4fc2b10945108cf1008ec9698291de6706ffcb73"
        },
        {
          "name": "https://github.com/cbcoutinho/nextcloud-mcp-server/tree/v0.117.2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/cbcoutinho/nextcloud-mcp-server/tree/v0.117.2"
        }
      ],
      "source": {
        "advisory": "GHSA-8vh3-g2qg-2h2c",
        "discovery": "UNKNOWN"
      },
      "title": "Nextcloud MCP Server: Unauthenticated `POST /webhooks/nextcloud` allows arbitrary vector data deletion when `WEBHOOK_SECRET` is unset ( default )"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55640",
    "datePublished": "2026-08-25T16:03:28.085Z",
    "dateReserved": "2026-06-16T23:52:12.057Z",
    "dateUpdated": "2026-08-25T19:20:43.689Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}