Security advisory

{
  "id": "b4c28ecc08b03b3bd9a1a45569a43e9045e7aff0c04259cea00ead17ac6eb06d",
  "url": "https://osv.dev/vulnerability/CVE-2021-30156",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-30156",
    "summary": "An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. Special:Contributions can leak that a \"hidden\" user exists.",
    "evidence": "osv:CVE-2021-30156",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-30156",
      "aliases": [
        "BIT-mediawiki-2021-30156",
        "CVE-2021-30156"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/wikimedia/mediawiki",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "ef13e11da4bcab62a8cc6f5459cd094e6881f326"
                },
                {
                  "introduced": "0fbb878ef366477535a709b0c2564bdcf4b176d1"
                },
                {
                  "fixed": "e5823c068a2e0d8af72538fe5cd152ddb43c58e9"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.31.12"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.32.0"
                      },
                      {
                        "fixed": "1.35.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.35.1",
            "1.31.11",
            "1.31.8",
            "1.35.0",
            "1.31.10",
            "1.31.9",
            "1.35.0-rc.3",
            "1.35.0-rc.2",
            "1.35.0-rc.1",
            "1.35.0-rc.0",
            "1.31.7",
            "1.31.6",
            "1.31.5",
            "1.31.4",
            "1.31.3",
            "1.31.2",
            "1.31.1",
            "1.31.0",
            "1.31.0-rc.2",
            "1.31.0-rc.1",
            "1.31.0-rc.0",
            "test-hashar-for-ci",
            "1.6.0",
            "1.5.0beta4",
            "1.5.0beta3",
            "1.5.0beta2",
            "1.5.0beta1",
            "1.5.0alpha2",
            "1.5.0alpha1",
            "1.3.0beta1",
            "1.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-30156.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:16.567162700Z",
      "provider": "osv",
      "references": [
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/26UJGHF7LJDOCQN6A3Z4PM7PYRKENJHE/",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2OMSV7B2TCFBOCICN3B4SMQP5HVRJQIT/",
        "https://phabricator.wikimedia.org/T276306"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
              "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "33"
                  },
                  {
                    "last_affected": "33"
                  },
                  {
                    "introduced": "34"
                  },
                  {
                    "last_affected": "34"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-30156",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 429372,
  "published_at": "2021-04-09T07:15:16.217+00:00"
}