{"cve":"CVE-2026-107296","nvd":{"published":"2026-10-08T17:17:15.390","modified":"2026-10-14T01:17:05.483","status":"Deferred","description":"msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, decoding a negative signed 64-bit integer modifies the corresponding bytes in the caller-provided input buffer while computing the value. Applications that retain or reuse encoded input for integrity checks, logging, or later processing can observe silently corrupted data, while positive integers and other MessagePack value types are unaffected. 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:L/A:N","score":3.7},"cwes":["CWE-471"],"references":["https://github.com/mcollina/msgpack5/commit/82b70393a824e1088a45a377548d1d9ab82faf91","https://github.com/mcollina/msgpack5/releases/tag/v6.1.0","https://github.com/mcollina/msgpack5/security/advisories/GHSA-qw35-55vc-rhgj"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:58:01.639778232+00:00"},"epss":{"cve":"CVE-2026-107296","score":0.00276,"percentile":0.19778,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-qw35-55vc-rhgj","url":"https://osv.dev/vulnerability/GHSA-qw35-55vc-rhgj","summary":"msgpack5: Decoding negative int64 values mutates the input buffer","modified":"2026-10-08T17:45:03.538503996Z","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."]}