server — security advisory

{
  "id": "81b9770f2595e1558a42b00554494d9cf74a0330cc318dec457d94bd5126eacb",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-77167",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-77167",
    "summary": "Abusing the federated share endpoint, an attacker can write arbitrary rows into the oc_share_external database table. These rows persist indefinitely — there is no automatic cleanup mechanism. Three distinct denial-of-service conditions follow from this write primitive, all triggered from the same unauthenticated source and all self-renewing on a 24-hour cycle for as long as the injected rows remain in the database.",
    "evidence": "cve:CVE-2026-77167",
    "products": [
      {
        "name": {
          "value": "server",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-77167",
      "aliases": [
        "CVE-2026-77167"
      ],
      "metrics": [
        {
          "cvssV3_0": {
            "version": "3.0",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
          }
        }
      ],
      "affected": [
        {
          "vendor": "Nextcloud",
          "product": "server",
          "versions": [
            {
              "status": "affected",
              "version": "22.0.0",
              "versionType": "semver",
              "lessThanOrEqual": "34.0.0"
            }
          ],
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-27T16:15:34.778Z",
      "provider": "cve",
      "references": [
        "https://hackerone.com/reports/3679640"
      ],
      "provider_metadata": {
        "cna": {
          "orgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1",
          "shortName": "hackerone",
          "dateUpdated": "2026-10-27T16:15:34.778Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-77167",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 394455,
  "published_at": "2026-10-27T16:15:34.778+00:00"
}