msgpack5: Truncated map32 headers throw an unexpected error

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-107302
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-08 18:17:19 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 decoder reads the four-byte length of a map32 value before validating that the complete five-byte header is available. A truncated map32 header therefore causes a checked out-of-bounds buffer read and throws RangeError instead of IncompleteBufferError, which can unexpectedly terminate a request, stream, or worker in applications that wait for additional bytes after IncompleteBufferError. There is no adjacent-memory disclosure because the buffer implementation checks bounds. This issue is fixed in version 6.1.0.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

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

Problem Types: CWE-125 | CWE-125 CWE-125: Out-of-bounds Read

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

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

CVSS:3.1/AV:N/AC:L/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-8f34-f56x-9xph [email protected] github.com
github.com/mcollina/msgpack5/commit/15443a1f2aa682a6aa37f1705ac628de5b86... [email protected] github.com
github.com/mcollina/msgpack5/releases/tag/v6.1.0 [email protected] github.com
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