msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, decoding a negative signed 64-bit integer modifies the corresponding bytes in the caller-provided input buffer while computing the value. Applications that retain or reuse encoded input for integrity checks, logging, or later processing can observe silently corrupted data, while positive integers and other MessagePack value types are unaffected. This issue is fixed in version 6.1.0.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-qw35-55vc-rhgj msgpack5: Decoding negative int64 values mutates the input buffer
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 08 Oct 2026 17:15:00 +0000

Type Values Removed Values Added
Description msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, decoding a negative signed 64-bit integer modifies the corresponding bytes in the caller-provided input buffer while computing the value. Applications that retain or reuse encoded input for integrity checks, logging, or later processing can observe silently corrupted data, while positive integers and other MessagePack value types are unaffected. This issue is fixed in version 6.1.0.
Title msgpack5: Decoding negative int64 values mutates the input buffer
Weaknesses CWE-471
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-10-08T17:05:34.059Z

Reserved: 2026-10-07T15:53:23.587Z

Link: CVE-2026-107296

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-08T17:17:15.390

Modified: 2026-10-08T17:17:15.390

Link: CVE-2026-107296

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses