{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0"
                  },
                  {
                    "fixed": "1.2.3"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "fixed": "620b0eb4c89cd72d4098564537624d9dbb2ce141"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "original_tag": "v1.2.3",
                "range": [
                  {
                    "fixed": "742cb6d7ad141343edcccc829b5b06d0c6f8fcb5"
                  }
                ],
                "source": "REFERENCES_TAG"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "742cb6d7ad141343edcccc829b5b06d0c6f8fcb5"
            },
            {
              "fixed": "620b0eb4c89cd72d4098564537624d9dbb2ce141"
            }
          ],
          "repo": "https://github.com/msgpack/msgpack-python",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-j586-36cw-2gc2"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-401"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114613.json"
  },
  "details": "MessagePack is the serializer implementation for Python msgpack.org. Prior to 1.2.3, the msgpack-python C extension (msgpack._cmsgpack) leaks a decoded map value when deserialization rejects a key with strict_map_key=True (the default). Repeated malformed inputs can cause unbounded process memory growth and denial of service in applications that deserialize attacker-controlled MessagePack data. Both unpackb() and the streaming Unpacker API are affected. The pure-Python fallback does not exhibit this leak in the reported tests. This issue is fixed in version 1.2.3.",
  "id": "CVE-2026-114613",
  "modified": "2026-10-23T10:30:21.934852917Z",
  "published": "2026-10-22T18:22:40.544Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/114xxx/CVE-2026-114613.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/msgpack/msgpack-python/commit/620b0eb4c89cd72d4098564537624d9dbb2ce141"
    },
    {
      "type": "WEB",
      "url": "https://github.com/msgpack/msgpack-python/releases/tag/v1.2.3"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/msgpack/msgpack-python/security/advisories/GHSA-j586-36cw-2gc2"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-114613"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "MessagePack: Unbounded memory leak in msgpack C extension on strict_map_key validation failure"
}