CVE-2026-107297
mediummsgpack5 is a msgpack v5 implementation for node.js and the browser.
msgpack5 is a msgpack v5 implementation for node.js and the browser. Prior to 6.1.0, the streaming decoder reparses an incomplete array or map from the beginning whenever another chunk arrives. A remote peer can split one valid MessagePack container across many small chunks, causing completed elements to be decoded repeatedly, producing quadratic CPU use and blocking the event loop. This issue is fixed in version 6.1.0.
CVSS
5.9
5.9 (CVSS v3.1)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Severity source: NVD CVSS v3.1 (security-advisories@github.com)
Timeline (UTC)
Published: 2026-10-08 17:17
Modified: 2026-10-08 20:48
NVD status: Deferred
Last synced 2 days ago
Verified against the source API 2026-10-27 06:58 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/mcollina/msgpack5/commit/e4827641d3105e295cbbd56e9c5389978547eab4 security-advisories@github.com
- https://github.com/mcollina/msgpack5/releases/tag/v6.1.0 security-advisories@github.com
- https://github.com/mcollina/msgpack5/security/advisories/GHSA-gcx5-hxj7-gpqq security-advisories@github.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 06:58 UTC · record ↗