Checkmate: Pre-auth Denial of Service via File Upload on Registration

{
  "id": "c19b3c105d2ae162b38f178e03b5de926653d39ae12a6b5fac82ed7b7ee1049a",
  "url": "https://osv.dev/vulnerability/CVE-2026-55241",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Checkmate: Pre-auth Denial of Service via File Upload on Registration",
    "summary": "Checkmate is an open-source, self-hosted tool designed to track and monitor server hardware, uptime, response times, and incidents in real-time with beautiful visualizations. Prior to 3.9.1, the public POST /api/v1/auth/register route in server/src/api/routes/authRoutes.ts passes multipart profileImage uploads through in-memory Multer parsing before registration validation, without file-size, file-count, or MIME-type limits in server/src/api/middleware/upload.ts. An unauthenticated attacker can submit concurrent oversized files that are buffered before invalid registration or invite-token checks reject the request, exhausting memory and crashing or destabilizing the backend. This issue is fixed in version 3.9.1.",
    "evidence": "osv:CVE-2026-55241",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-55241",
      "aliases": [
        "CVE-2026-55241",
        "GHSA-9xvg-x28f-m78m"
      ],
      "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/bluewave-labs/checkmate",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "825bcc5fdbd0dbde9e78033ce844ab880a46083a"
                },
                {
                  "fixed": "091c36cbf338b673110b0806d76df26d52516468"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.9.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "091c36cbf338b673110b0806d76df26d52516468"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "825bcc5fdbd0dbde9e78033ce844ab880a46083a"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.9.1"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.8.1",
            "v3.8.0",
            "untagged-819f0fe0d99d8d0b5f14",
            "v3.7.1",
            "v3.6.1",
            "v3.5.1",
            "v3.5.0",
            "v3.4.0",
            "v3.3",
            "v3.2.0",
            "v3.1.8",
            "v3.1.7",
            "v3.1.6",
            "v3.1.5",
            "v3.1.4",
            "v3.1.3",
            "v3.1.2",
            "v3.1.1",
            "v3.1",
            "v3.1-beta",
            "V3.0-beta",
            "v2.3.1",
            "v2.3",
            "v2.2",
            "v2.1.1",
            "v2.1",
            "v2.0.2",
            "v2.0.1",
            "v1.1.0",
            "v1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55241.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.920370215Z",
      "provider": "osv",
      "references": [
        "https://github.com/bluewave-labs/Checkmate/releases/tag/v3.9.1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55241.json",
        "https://github.com/bluewave-labs/Checkmate/security/advisories/GHSA-9xvg-x28f-m78m",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-55241",
        "https://github.com/bluewave-labs/Checkmate/commit/091c36cbf338b673110b0806d76df26d52516468"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-400",
          "CWE-770"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55241.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-55241",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 510930,
  "published_at": "2026-08-21T17:57:10.014+00:00"
}