{"id":"GHSA-gcx5-hxj7-gpqq","summary":"msgpack5: Quadratic parsing in the streaming decoder","details":"### Impact\n\nThe streaming decoder reparses an incomplete container from the beginning whenever another chunk arrives. A remote peer can split one valid MessagePack value across many small chunks, causing quadratic CPU usage and blocking the event loop.\n\n### Patches\n\nThe decoder now preserves incremental container state so completed elements are not parsed again when more input arrives.\n\n### Workarounds\n\nBuffer each complete MessagePack value before decoding it, or limit the number of chunks accepted for a single value.","aliases":["CVE-2026-107297"],"modified":"2026-10-08T18:00:08.904462199Z","published":"2026-10-08T17:39:46Z","database_specific":{"github_reviewed_at":"2026-10-08T17:39:46Z","nvd_published_at":null,"cwe_ids":["CWE-407"],"severity":"MODERATE","github_reviewed":true},"references":[{"type":"WEB","url":"https://github.com/mcollina/msgpack5/security/advisories/GHSA-gcx5-hxj7-gpqq"},{"type":"WEB","url":"https://github.com/mcollina/msgpack5/commit/e4827641d3105e295cbbd56e9c5389978547eab4"},{"type":"PACKAGE","url":"https://github.com/mcollina/msgpack5"},{"type":"WEB","url":"https://github.com/mcollina/msgpack5/releases/tag/v6.1.0"}],"affected":[{"package":{"name":"msgpack5","ecosystem":"npm","purl":"pkg:npm/msgpack5"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"6.1.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-gcx5-hxj7-gpqq/GHSA-gcx5-hxj7-gpqq.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}