{"cve":"CVE-2026-107299","nvd":{"published":"2026-10-08T17:17:15.850","modified":"2026-10-09T16:17:22.147","status":"Deferred","description":"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 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","score":5.9},"cwes":["CWE-228"],"references":["https://github.com/mcollina/msgpack5/commit/85da345bf1acc18ca441741e5cf4aa0ed0d69314","https://github.com/mcollina/msgpack5/releases/tag/v6.1.0","https://github.com/mcollina/msgpack5/security/advisories/GHSA-26wq-p25c-j6fv"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:58:01.639778232+00:00"},"epss":{"cve":"CVE-2026-107299","score":0.00389,"percentile":0.32699,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-26wq-p25c-j6fv","url":"https://osv.dev/vulnerability/GHSA-26wq-p25c-j6fv","summary":"msgpack5: Reserved byte can cause unbounded stream buffering","modified":"2026-10-08T18:00:08.901031374Z","packages":[{"ecosystem":"npm","name":"msgpack5","purl":"pkg:npm/msgpack5","ranges":["<6.1.0"],"fixed":["6.1.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}