Denial of service in github.com/shamaton/msgpack

The msgpack decoder fails to properly validate the input buffer length when processing truncated fixext data (format codes 0xd4-0xd8). This can lead to an out-of-bounds read and a runtime panic, allowing a denial of service attack.

Problem type

CWE-125: Out-of-bounds Read

Affected products

github.com/shamaton/msgpack

github.com/shamaton/msgpack

github.com/shamaton/msgpack/v2

github.com/shamaton/msgpack/v2

github.com/shamaton/msgpack/v3

github.com/shamaton/msgpack/v3

References

github.com

https://github.com/shamaton/msgpack/issues/59

github.com

https://github.com/golang/vulndb/issues/4513

pkg.go.dev

https://pkg.go.dev/vuln/GO-2026-4513

JSON source

https://cveawg.mitre.org/api/cve/CVE-2026-32284

Click to expand

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    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "dateUpdated": "2026-03-26T19:40:51.686Z",
    "dateReserved": "2026-03-11T16:38:46.556Z",
    "datePublished": "2026-03-26T19:40:51.686Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
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        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go",
        "dateUpdated": "2026-03-26T19:40:51.686Z"
      },
      "title": "Denial of service in github.com/shamaton/msgpack",
      "descriptions": [
        {
          "lang": "en",
          "value": "The msgpack decoder fails to properly validate the input buffer length when processing truncated fixext data (format codes 0xd4-0xd8). This can lead to an out-of-bounds read and a runtime panic, allowing a denial of service attack."
        }
      ],
      "affected": [
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              "name": "Unmarshal"
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          "url": "https://github.com/golang/vulndb/issues/4513"
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