{"id":"CVE-2026-107299","title":"msgpack5 is a msgpack v5 implementation for node.js and the browser","summary":"msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, the streaming decoder treats the reserved MessagePack byte 0xc1 as incomplete input instead of invalid input. When 0xc1 begins a stream, subsequent data…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-228"],"vendor":"msgpack5","product":"msgpack5","affected":["msgpack5 < 6.1.0"],"patched":["msgpack5 6.1.0"],"published":"2026-10-08","updated":"2026-10-08","sourceUpdated":"2026-10-08T20:48:36.970","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-107299","references":[{"url":"https://github.com/mcollina/msgpack5/commit/85da345bf1acc18ca441741e5cf4aa0ed0d69314","label":"security-advisories@github.com"},{"url":"https://github.com/mcollina/msgpack5/releases/tag/v6.1.0","label":"security-advisories@github.com"},{"url":"https://github.com/mcollina/msgpack5/security/advisories/GHSA-26wq-p25c-j6fv","label":"security-advisories@github.com"},{"url":"https://github.com/advisories/GHSA-26wq-p25c-j6fv"}],"tags":["nvd","ghsa","npm","cve.org"],"aliases":["GHSA-26wq-p25c-j6fv"],"ecosystem":"npm","ingestedAt":"2026-10-08T17:56:11.715Z","slug":"CVE-2026-107299","body":"## Overview\n\nmsgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, the streaming decoder treats the reserved MessagePack byte 0xc1 as incomplete input instead of invalid input. When 0xc1 begins a stream, subsequent data remains buffered while the decoder waits for bytes that cannot make the value valid, allowing a remote peer to exhaust memory. This issue is fixed in version 6.1.0.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-107299)\n\nAffected packages:\n\n- `msgpack5 < 6.1.0`\n\nPatched in:\n\n- `msgpack5 6.1.0`\n\nSource: https://github.com/advisories/GHSA-26wq-p25c-j6fv","depth":"sunlit","depthScore":32,"depthScoreParts":{"impact":32.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}