{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.5.19"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "e9123ad691727ffec3672ff3912ef56e67c930ef"
            }
          ],
          "repo": "https://github.com/mastodon/mastodon",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "4.0.0"
              },
              {
                "fixed": "4.0.15"
              }
            ]
          },
          "events": [
            {
              "introduced": "fb389bd73c8a4bc2924496f6041c8eee27572d21"
            },
            {
              "fixed": "e5726d211fd3dc1d640f202e808e25891d765586"
            }
          ],
          "repo": "https://github.com/mastodon/mastodon",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "4.1.0"
              },
              {
                "fixed": "4.1.15"
              }
            ]
          },
          "events": [
            {
              "introduced": "61c5dfb9295ea66c376c452a7ef7379e8c562416"
            },
            {
              "fixed": "b7b03e8d26a4344ef331ba667c16311110a0d6dd"
            }
          ],
          "repo": "https://github.com/mastodon/mastodon",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "4.2.0"
              },
              {
                "fixed": "4.2.7"
              }
            ]
          },
          "events": [
            {
              "introduced": "4fcc026f0f1b12a9de21a3af33375a9c8867dd55"
            },
            {
              "fixed": "0e4e98fad1e21e4f356b3a71eef3fca79890105c"
            }
          ],
          "repo": "https://github.com/mastodon/mastodon",
          "type": "GIT"
        }
      ]
    },
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.5.19"
              },
              {
                "introduced": "4.0.0"
              },
              {
                "fixed": "4.0.15"
              },
              {
                "introduced": "4.1.0"
              },
              {
                "fixed": "4.1.15"
              },
              {
                "introduced": "4.2.0"
              },
              {
                "fixed": "4.2.7"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "e9123ad691727ffec3672ff3912ef56e67c930ef"
            },
            {
              "introduced": "fb389bd73c8a4bc2924496f6041c8eee27572d21"
            },
            {
              "fixed": "e5726d211fd3dc1d640f202e808e25891d765586"
            },
            {
              "introduced": "61c5dfb9295ea66c376c452a7ef7379e8c562416"
            },
            {
              "fixed": "b7b03e8d26a4344ef331ba667c16311110a0d6dd"
            },
            {
              "introduced": "4fcc026f0f1b12a9de21a3af33375a9c8867dd55"
            },
            {
              "fixed": "0e4e98fad1e21e4f356b3a71eef3fca79890105c"
            }
          ],
          "repo": "https://github.com/tootsuite/mastodon",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-jhrq-qvrm-qr36"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-434"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/25xxx/CVE-2024-25623.json"
  },
  "details": "Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19, when fetching remote statuses, Mastodon doesn't check that the response from the remote server has a `Content-Type` header value of the Activity Streams media type, which allows a threat actor to upload a crafted Activity Streams document to a remote server and make a Mastodon server fetch it, if the remote server accepts arbitrary user uploads. The vulnerability allows a threat actor to impersonate an account on a remote server that satisfies all of the following properties: allows the attacker to register an account; accepts arbitrary user-uploaded documents and places them on the same domain as the ActivityPub actors; and serves user-uploaded document in response to requests with an `Accept` header value of the Activity Streams media type. Versions 4.2.7, 4.1.15, 4.0.15, and 3.5.19 contain a fix for this issue.",
  "id": "CVE-2024-25623",
  "modified": "2026-04-01T23:10:23.992139989Z",
  "published": "2024-02-19T15:28:15.296Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/25xxx/CVE-2024-25623.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-jhrq-qvrm-qr36"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-25623"
    },
    {
      "type": "FIX",
      "url": "https://github.com/mastodon/mastodon/commit/9fee5e852669e26f970e278021302e1a203fc022"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Lack of media type verification of Activity Streams objects allows impersonation of remote accounts"
}