msgpack5: Quadratic parsing in the streaming decoder

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-107297
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-08 17:17:15 UTC
Updated2026-10-08 20:48:36 UTC
Descriptionmsgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, the streaming decoder reparses an incomplete array or map from the beginning whenever another chunk arrives. A remote peer can split one valid MessagePack container across many small chunks, causing completed elements to be decoded repeatedly, producing quadratic CPU use and blocking the event loop. This issue is fixed in version 6.1.0.

Risk And Classification

Primary CVSS: v3.1 5.9 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Problem Types: CWE-407 | CWE-407 CWE-407: Inefficient Algorithmic Complexity

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.9MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED5.9MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Mcollina Msgpack5 affected < 6.1.0 Not specified

References

ReferenceSourceLinkTags
github.com/mcollina/msgpack5/security/advisories/GHSA-gcx5-hxj7-gpqq [email protected] github.com
github.com/mcollina/msgpack5/releases/tag/v6.1.0 [email protected] github.com
github.com/mcollina/msgpack5/commit/e4827641d3105e295cbbd56e9c5389978547... [email protected] github.com
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