Security advisory

{
  "id": "f0561c9efc7ea643acd2b7aa5a6cad4e367b4a1643b5f2dc3a6dc3badcda4bd3",
  "url": "https://osv.dev/vulnerability/CVE-2020-8139",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-8139",
    "summary": "A missing access control check in Nextcloud Server < 18.0.1, < 17.0.4, and < 16.0.9 causes hide-download shares to be downloadable when appending /download to the URL.",
    "evidence": "osv:CVE-2020-8139",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2020-8139",
      "aliases": [
        "CVE-2020-8139"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/nextcloud/server",
              "type": "GIT",
              "events": [
                {
                  "introduced": "6781f9fc7652f735a75abd869ab3e79878fceec9"
                },
                {
                  "fixed": "a02107dcb67fdeac7f5b39849a2206b4c20e3559"
                },
                {
                  "introduced": "c937c8f1753b111086e28afa396f3abd5776b1db"
                },
                {
                  "fixed": "db077774e6f893610419a96efc385e5d2cdf111d"
                },
                {
                  "introduced": "fe6fdfe50de3d46e0ae18ce5b2f216855004df4f"
                },
                {
                  "fixed": "f6bd5afd0370ae6308529047ba6344acf8d382a3"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "16.0.0"
                      },
                      {
                        "fixed": "16.0.9"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "17.0.0"
                      },
                      {
                        "fixed": "17.0.4"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "18.0.0"
                      },
                      {
                        "fixed": "18.0.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v16.0.9RC2",
            "v17.0.4RC2",
            "v16.0.9RC1",
            "v17.0.4RC1",
            "v18.0.1RC3",
            "v18.0.1RC2",
            "v18.0.1RC1",
            "v16.0.8",
            "v17.0.3",
            "v16.0.8RC1",
            "v17.0.3RC1",
            "v18.0.0",
            "v16.0.7",
            "v17.0.2",
            "v16.0.7RC1",
            "v17.0.2RC1",
            "v17.0.1",
            "v16.0.6",
            "v16.0.6rc1",
            "v17.0.1rc1",
            "v17.0.0",
            "v16.0.5",
            "v16.0.5RC1",
            "v16.0.4",
            "16.0.4",
            "v16.0.4RC1",
            "v16.0.3",
            "v16.0.2",
            "v16.0.2RC1",
            "v16.0.1",
            "v16.0.1RC1",
            "v16.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-8139.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:50.839455583Z",
      "provider": "osv",
      "references": [
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KC6HLX5SG4PZO6Y54D2LFJ4ATG76BKOP/",
        "https://nextcloud.com/security/advisory/?id=NC-SA-2020-015",
        "https://hackerone.com/reports/788257"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "32"
                  },
                  {
                    "last_affected": "32"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2020-8139",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 437345,
  "published_at": "2020-03-20T21:15:17.64+00:00"
}