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MediumFix available

msgpack5: Deeply nested input can exhaust the decoder stack

Type: advisorySources: OSV

### Impact The decoder has no nesting-depth limit for arrays and maps. An attacker who can provide MessagePack input can use deeply nested containers to exhaust the JavaScript call stack and interrupt the process or request handler. ### Patches The decoder now limits nesting depth to 100 by default and throws `Maximum decode depth exceeded`. Applications can configure the limit with the `maxDepth` option. ### Workarounds Reject deeply nested input before decoding, isolate decoding in a worker, or enforce a trusted schema with a bounded nesting depth.

Products
msgpack5
Affected versions
Not specified
Fixed versions
6.1.0
CVEs
CVE-2026-107298
Confirmed fixed CVEs
Not specified
Updated in this feed
28 Oct 2026, 10:03 UTC · Revision 1

Source evidence

msgpack5: Deeply nested input can exhaust the decoder stack

core-osv · Original source

Published 8 Oct 2026, 17:39 UTC

### Impact The decoder has no nesting-depth limit for arrays and maps. An attacker who can provide MessagePack input can use deeply nested containers to exhaust the JavaScript call stack and interrupt the process or request handler. ### Patches The decoder now limits nesting depth to 100 by default and throws `Maximum decode depth exceeded`. Applications can configure the limit with the `maxDepth` option. ### Workarounds Reject deeply nested input before decoding, isolate decoding in a worker, or enforce a trusted schema with a bounded nesting depth.

osv:GHSA-24ch-f2g6-9hhh

msgpack5

Fixed versions: 6.1.0

Complete source record
{
  "id": "0b4de3816e2f3f313b27f0bf6776cbbbec183d68d37279b7108fc31ab182b986",
  "url": "https://osv.dev/vulnerability/GHSA-24ch-f2g6-9hhh",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "msgpack5: Deeply nested input can exhaust the decoder stack",
    "summary": "### Impact The decoder has no nesting-depth limit for arrays and maps. An attacker who can provide MessagePack input can use deeply nested containers to exhaust the JavaScript call stack and interrupt the process or request handler. ### Patches The decoder now limits nesting depth to 100 by default and throws `Maximum decode depth exceeded`. Applications can configure the limit with the `maxDepth` option. ### Workarounds Reject deeply nested input before decoding, isolate decoding in a worker, or enforce a trusted schema with a bounded nesting depth.",
    "evidence": "osv:GHSA-24ch-f2g6-9hhh",
    "products": [
      {
        "name": {
          "value": "msgpack5",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.1.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "GHSA-24ch-f2g6-9hhh",
      "aliases": [
        "CVE-2026-107298",
        "GHSA-24ch-f2g6-9hhh"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "6.1.0"
                }
              ]
            }
          ],
          "package": {
            "name": "msgpack5",
            "purl": "pkg:npm/msgpack5",
            "ecosystem": "npm"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-24ch-f2g6-9hhh/GHSA-24ch-f2g6-9hhh.json"
          }
        }
      ],
      "modified": "2026-10-08T18:00:09.700213613Z",
      "provider": "osv",
      "references": [
        "https://github.com/mcollina/msgpack5/security/advisories/GHSA-24ch-f2g6-9hhh",
        "https://github.com/mcollina/msgpack5/commit/1e2b5874e555dd7c99417f64788a03b0590bb102",
        "https://github.com/mcollina/msgpack5",
        "https://github.com/mcollina/msgpack5/releases/tag/v6.1.0"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-674"
        ],
        "severity": "MODERATE",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-08T17:39:51Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-107298",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 104435,
  "published_at": "2026-10-08T17:39:51+00:00"
}