---
id: CVE-2026-32284
title: >-
  The msgpack decoder fails to properly validate the input buffer length when
  processing truncated fixext data (format codes 0xd4-0xd8)
summary: >-
  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.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-125
vendor: shamaton
product: msgpack
affected:
  - msgpack <= 3.1.2
published: '2026-03-26'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T18:17:20.127'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-32284'
references:
  - url: 'https://github.com/golang/vulndb/issues/4513'
    label: security@golang.org
  - url: 'https://github.com/shamaton/msgpack/issues/59'
    label: security@golang.org
  - url: 'https://pkg.go.dev/vuln/GO-2026-4513'
    label: security@golang.org
  - url: >-
      https://securityinfinity.com/research/shamaton-msgpack-oob-panic-fixext-dos-2026
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-03-30T14:04:12.686407Z'
epss: 0.00695
epssPercentile: 0.51469
ingestedAt: '2026-10-07T18:42:20.879Z'
---

## Overview

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

- `msgpack <= 3.1.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.