A AegiFlow
MEDIUMCVSS 6.5EPSS 0.4%

CVE-2026-107301

CVE-2026-107301 updated by NVD

Published
2026-10-08
Modified
2026-10-16
EPSS percentile
28%
Sources
github-advisory, nvd

Summary

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.

Affected packages

EcosystemPackageAffected versionsFixed versions
npmmsgpack5—6.1.0

Remediation: Upgrade to 6.1.0 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.

CVE® is a registered trademark of The MITRE Corporation. CVE content reproduced under the CVE Terms of Use; copyright designation © MITRE.

EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.