{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2024-48924",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2024-48924",
    "idYear": 2024,
    "status": "PUBLISHED",
    "publishedAt": "2024-10-17T20:36:40.570Z",
    "updatedAt": "2024-10-18T17:20:11.062Z",
    "importedAt": "2026-10-24T01:57:16.009Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "MessagePack allows untrusted data to lead to DoS attack due to hash collisions and stack overflow",
      "summary": "### Impact\n\nWhen this library is used to deserialize messagepack data from an untrusted source, there is a risk of a denial of service attack by an attacker that sends data contrived to produce hash collisions, leading to large CPU consumption disproportionate to the size of the data being deserialized.\n\nThis is similar to [a prior advisory](https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-7q36-4xx7-xcxf), which provided an inadequate fix for the hash collision part of the vulnerability.\n\n### Patches\n\nThe following steps are required to mitigate this risk.\n\n1. Upgrade to a version of the library where a fix is available.\n1. Review the steps in [this previous advisory](https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-7q36-4xx7-xcxf) to ensure you have your application configured for untrusted data.\n\n### Workarounds\n\nIf upgrading MessagePack to a patched version is not an option for you, you may apply a manual workaround as follows:\n\n1. Declare a class that derives from `MessagePackSecurity`.\n2. Override the `GetHashCollisionResistantEqualityComparer<T>` method to provide a collision-resistant hash function of your own and avoid calling `base.GetHashCollisionResistantEqualityComparer<T>()`.\n3. Configure a `MessagePackSerializerOptions` with an instance of your derived type by calling `WithSecurity` on an existing options object.\n4. Use your custom options object for all deserialization operations. This may be by setting the `MessagePackSerializer.DefaultOptions` static property, if you call methods that rely on this default property, and/or by passing in the options object explicitly to any `Deserialize` method.\n\n### References\n\n- Learn more about best security practices when reading untrusted data with [MessagePack 1.x](https://github.com/MessagePack-CSharp/MessagePack-CSharp/tree/v1.x#security) or [MessagePack 2.x](https://github.com/MessagePack-CSharp/MessagePack-CSharp#security).\n- The .NET team's [discussion on hash collision vulnerabilities of their `HashCode` struct](https://github.com/GrabYourPitchforks/runtime/blob/threat_models/docs/design/security/System.HashCode.md).\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n* [Start a public discussion](https://github.com/MessagePack-CSharp/MessagePack-CSharp/discussions)\n* [Email us privately](mailto:andrewarnott@live.com)",
      "affected": [
        {
          "vendor": "MessagePack-CSharp",
          "product": "MessagePack-CSharp",
          "versions": [
            {
              "version": "< 2.5.187",
              "status": "affected"
            },
            {
              "version": ">= 2.6.95-alpha, < 3.0.214-rc.1",
              "status": "affected"
            }
          ]
        }
      ]
    }
  }
}