Mastodon: Persistent anonymous DoS via unhandled NoMethodError in MATH_TRANSFORMER

{
  "id": "bd23c5c6be7e02afa1107ef15350291db31b77916ac5e699593edb0d508f2e3a",
  "url": "https://osv.dev/vulnerability/CVE-2026-50129",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Mastodon: Persistent anonymous DoS via unhandled NoMethodError in MATH_TRANSFORMER",
    "summary": "Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.11, 4.4.18, and 4.3.24, a DoS can be triggered by (Uncaught Exception vulerability), due to missing exception handling in the math sanitizer. Malformed nodes can result in a DoS of a whole server or targeted users services, depending on the type of action that includes the malformed nodes and the services interacting with it. This vulnerability is fixed in 4.5.11, 4.4.18, and 4.3.24.",
    "evidence": "osv:CVE-2026-50129",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-50129",
      "aliases": [
        "BIT-mastodon-2026-50129",
        "CVE-2026-50129",
        "GHSA-qrgq-9fx2-vf2r"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mastodon/mastodon",
              "type": "GIT",
              "events": [
                {
                  "introduced": "5a8ab0a3e62a8825e28bb74c1760ba6488d20c97"
                },
                {
                  "fixed": "0748a5ff81b24e666ab10b8ee7fbc6f0362c8cb0"
                },
                {
                  "introduced": "12c0e58d9aa80db570fba5fa5146f3a640e99b42"
                },
                {
                  "fixed": "3555d595e2a6fcf425c73f783e8709b1e44c0872"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "4.5.0-beta.1"
                      },
                      {
                        "fixed": "4.5.11"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "4.4.0-beta.1"
                      },
                      {
                        "fixed": "4.4.18"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v4.4.17",
            "v4.5.10",
            "v4.4.16",
            "v4.5.9",
            "v4.4.15",
            "v4.5.8",
            "v4.4.14",
            "v4.5.7",
            "v4.5.6",
            "v4.4.13",
            "v4.4.12",
            "v4.5.5",
            "v4.5.4",
            "v4.4.11",
            "v4.5.3",
            "v4.4.10",
            "v4.5.2",
            "v4.4.9",
            "v4.5.1",
            "v4.5.0",
            "v4.4.8",
            "v4.5.0-rc.3",
            "v4.5.0-rc.2",
            "v4.5.0-rc.1",
            "v4.5.0-beta.2",
            "v4.4.7",
            "v4.5.0-beta.1",
            "v4.4.6",
            "v4.4.5",
            "v4.4.4",
            "v4.4.3",
            "v4.4.2",
            "v4.4.1",
            "v4.4.0",
            "v4.4.0-rc.1",
            "v4.4.0-beta.2",
            "v4.4.0-beta.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50129.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:50.346675368Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50129.json",
        "https://github.com/mastodon/mastodon/security/advisories/GHSA-qrgq-9fx2-vf2r",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50129"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-248"
        ],
        "cna_assigner": "GitHub_M",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "4.3.24"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50129.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-50129",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 518900,
  "published_at": "2026-06-24T19:50:51.968+00:00"
}