mcollina msgpack5 up to 6.0.x Deserialization options improperly controlled sequential memory allocation

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k2.09+

Summaryinfo

A vulnerability, which was classified as critical, was found in mcollina msgpack5 up to 6.0.x. This affects an unknown part of the component Deserialization. The manipulation of the argument options results in improperly controlled sequential memory allocation. This vulnerability is cataloged as CVE-2026-107301. The attack may be launched remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in mcollina msgpack5 up to 6.0.x. Affected is some unknown functionality of the component Deserialization. The manipulation of the argument options with an unknown input leads to a improperly controlled sequential memory allocation vulnerability. CWE is classifying the issue as CWE-1325. The product manages a group of objects or resources and performs a separate memory allocation for each object, but it does not properly limit the total amount of memory that is consumed by all of the combined objects. This is going to have an impact on integrity, and availability. CVE summarizes:

msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, constructing msgpack5 with an empty or partial options object disables the default protoAction: 'error' protection. A decoded map containing a __proto__ key can then replace the decoded object's prototype, potentially changing inherited properties or downstream behavior, although Object.prototype is not modified globally. This issue is fixed in version 6.1.0.

The advisory is available at github.com. This vulnerability is traded as CVE-2026-107301 since 10/07/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details are known, but there is no available exploit.

Upgrading to version 6.1.0 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.3

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improperly controlled sequential memory allocation
CWE: CWE-1325
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: msgpack5 6.1.0

Timelineinfo

10/07/2026 CVE reserved
10/08/2026 +1 days Advisory disclosed
10/08/2026 +0 days VulDB entry created
10/08/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-107301 (🔒)
GCVE (CVE): GCVE-0-2026-107301
GCVE (VulDB): GCVE-100-415494

Entryinfo

Created: 10/08/2026 19:33
Changes: 10/08/2026 19:33 (65)
Complete: 🔍
Cache ID: 216::103

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