{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6B2706E5-A6D0-4790-A3E6-5DE023465AB2",
              "versionEndExcluding": "4.3.17",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "DD92863A-CB76-45AA-BF4D-9870B24E8109",
              "versionEndExcluding": "4.4.11",
              "versionStartIncluding": "4.4.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "3E8FBAF5-C7BC-4980-9780-50BA935D126B",
              "versionEndExcluding": "4.5.4",
              "versionStartIncluding": "4.5.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Mastodon is a free, open-source social network server based on ActivityPub. Mastodon 4.3 added notifications of severed relationships, allowing end-users to inspect the relationships they lost as the result of a moderation action. The code allowing users to download lists of severed relationships for a particular event fails to check the owner of the list before returning the lost relationships. Any registered local user can access the list of lost followers and followed users caused by any severance event, and go through all severance events this way. The leaked information does not include the name of the account which has lost follows and followers. This has been fixed in Mastodon v4.3.17, v4.4.11 and v4.5.4."
    },
    {
      "lang": "es",
      "value": "Mastodon es un servidor de red social gratuito, de c\u00f3digo abierto, basado en ActivityPub. Mastodon 4.3 a\u00f1adi\u00f3 notificaciones de relaciones cortadas, permitiendo a los usuarios finales inspeccionar las relaciones que perdieron como resultado de una acci\u00f3n de moderaci\u00f3n. El c\u00f3digo que permite a los usuarios descargar listas de relaciones cortadas para un evento particular no verifica al propietario de la lista antes de devolver las relaciones perdidas. Cualquier usuario local registrado puede acceder a la lista de seguidores perdidos y usuarios seguidos causada por cualquier evento de corte, y revisar todos los eventos de corte de esta manera. La informaci\u00f3n filtrada no incluye el nombre de la cuenta que ha perdido seguimientos y seguidores. Esto ha sido corregido en Mastodon v4.3.17, v4.4.11 y v4.5.4."
    }
  ],
  "id": "CVE-2026-22246",
  "lastModified": "2026-01-22T13:52:28.883",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-01-08T16:16:02.957",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/mastodon/mastodon/commit/68e30985ca7afdb89af1b2e9dc962e1993dc8076"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/mastodon/mastodon/commit/b2bcd34486fd6681cc0f30028086ef0f47282adf"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/mastodon/mastodon/commit/c1fb6893c5175d74c074f6f786d504c8bc610d57"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-ww85-x9cp-5v24"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-201"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}