Vault unauthenticated denial of service through complex json payload

{
  "id": "b95880c149e2d633e704435d2db50989624898d99d6eb14b4f8b5dc7c0feef55",
  "url": "https://osv.dev/vulnerability/CVE-2025-6203",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vault unauthenticated denial of service through complex json payload",
    "summary": "A malicious user may submit a specially-crafted complex payload that otherwise meets the default request size limit which results in excessive memory and CPU consumption of Vault. This may lead to a timeout in Vault’s auditing subroutine, potentially resulting in the Vault server to become unresponsive. This vulnerability, CVE-2025-6203, is fixed in Vault Community Edition 1.20.3 and Vault Enterprise 1.20.3, 1.19.9, 1.18.14, and 1.16.25.",
    "evidence": "osv:CVE-2025-6203",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2025-6203",
      "aliases": [
        "BIT-vault-2025-6203",
        "CVE-2025-6203",
        "GHSA-8f82-53h8-2p34",
        "GO-2025-3924"
      ],
      "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/hashicorp/vault",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b4d07277a6c5318bb50d3b94bbd6135dccb4c601"
                },
                {
                  "fixed": "818ca8b3575ea937ca48b640baf35e1b2ede1833"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "1.15.0"
                      },
                      {
                        "fixed": "1.21.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "cpe": "cpe:2.3:a:hashicorp:vault:*:*:*:*:-:*:*:*",
                    "range": [
                      {
                        "introduced": "1.15.0"
                      },
                      {
                        "fixed": "1.21.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-6203.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:46.202960592Z",
      "provider": "osv",
      "references": [
        "https://discuss.hashicorp.com/t/hcsec-2025-24-vault-denial-of-service-though-complex-json-payloads/76393",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/6xxx/CVE-2025-6203.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-6203",
        "https://github.com/hashicorp/vault"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-770"
        ],
        "cna_assigner": "HashiCorp",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "1.15.0"
                  },
                  {
                    "fixed": "1.20.5"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "ChangesAt"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/6xxx/CVE-2025-6203.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-6203",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 514378,
  "published_at": "2025-08-28T19:36:09.87+00:00"
}