CVE-2026-32284: Github.com/shamaton/msgpack/v2 Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-h9q6-hc68-35rp
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CVSS 7.5
CWE-125
Published
Advisory Summary

CVE-2026-32284 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-125: Out-of-bounds Read) affecting Github.com/shamaton/msgpack/v2 libraries in the Go ecosystem. The issue involves denial of service in github.com/shamaton/msgpack. Remediation is available in the latest vendor maintenance releases.

CVE-2026-32284 at a Glance

CVE Identifier CVE-2026-32284
GHSA Identifier GHSA-h9q6-hc68-35rp
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-125: Out-of-bounds Read
Affected Product Github.com/shamaton/msgpack/v2
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-32284

To remediate this vulnerability, upgrade all affected Github.com/shamaton/msgpack/v2 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/shamaton/msgpack/v2 fixed: Latest secure release 
Upgrade github.com/shamaton/msgpack/v2 to Latest secure release
github.com/shamaton/msgpack/v3 fixed: Latest secure release 
Upgrade github.com/shamaton/msgpack/v3 to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/shamaton/msgpack/v2

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-32284, inspect your project dependencies for Github.com/shamaton/msgpack/v2:

inspect dependencies for github.com/shamaton/msgpack/v2

Analyze the terminal output to locate any version of Github.com/shamaton/msgpack/v2 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-125: Out-of-bounds Read, where the product reads data past the end, or before the beginning, of the intended buffer. In Github.com/shamaton/msgpack/v2, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2026-32284 Affected Github.com/shamaton/msgpack/v2 Versions

2 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
github.com/shamaton/msgpack/v2
golang/github.com/shamaton/msgpack/v2
Go
≤ 2.4.0
github.com/shamaton/msgpack/v3
golang/github.com/shamaton/msgpack/v3
Go
≤ 3.1.0

References

NVD — CVE-2026-32284 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-32284
Github.com/shamaton/msgpack/v2 Source Repository REPOSITORY
https://github.com/golang/vulndb/issues/4513
Github.com/shamaton/msgpack/v2 Source Repository REPOSITORY
https://github.com/shamaton/msgpack/issues/59
Github.com/shamaton/msgpack/v2 Source Repository REPOSITORY
https://github.com/shamaton/msgpack
pkg.go.dev/vuln/go-2026-4513 WEB
https://pkg.go.dev/vuln/GO-2026-4513
Github.com/shamaton/msgpack/v2 Security Information SECURITY
https://securityinfinity.com/research/shamaton-msgpack-oob-panic-fixext-dos-2026

Frequently Asked Questions

What is CVE-2026-32284?
CVE-2026-32284 is a security vulnerability in Github.com/shamaton/msgpack/v2 involving Denial of service in github.com/shamaton/msgpack under CWE-125: Out-of-bounds Read.
Which Github.com/shamaton/msgpack/v2 versions are affected?
Affected versions include releases prior to current release patches across affected packages: github.com/shamaton/msgpack/v2, github.com/shamaton/msgpack/v3.
What version fixes CVE-2026-32284?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/shamaton/msgpack/v2 affected?
Yes, github.com/shamaton/msgpack/v2 is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
Is github.com/shamaton/msgpack/v3 affected?
Yes, github.com/shamaton/msgpack/v3 is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-32284?
CVE-2026-32284 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-32284?
CVE-2026-32284 is classified under CWE-125: Out-of-bounds Read (The product reads data past the end, or before the beginning, of the intended buffer.).
How can I check Go dependencies for CVE-2026-32284?
Run the dependency tree command: 'inspect dependencies for github.com/shamaton/msgpack/v2'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-h9q6-hc68-35rp",
  "modified" : "2026-03-30T13:57:05Z",
  "published" : "2026-03-18T12:59:54Z",
  "aliases" : [ "CVE-2026-32284" ],
  "summary" : "Denial of service in github.com/shamaton/msgpack",
  "details" : "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" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/shamaton/msgpack/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "2.4.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/shamaton/msgpack/v3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "3.1.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-32284"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/golang/vulndb/issues/4513"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/shamaton/msgpack/issues/59"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/shamaton/msgpack"
  }, {
    "type" : "WEB",
    "url" : "https://pkg.go.dev/vuln/GO-2026-4513"
  }, {
    "type" : "WEB",
    "url" : "https://securityinfinity.com/research/shamaton-msgpack-oob-panic-fixext-dos-2026"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-125" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-18T12:59:54Z",
    "nvd_published_at" : "2026-03-26T20:16:12Z"
  }
}