CVE-2026-107299
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 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
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: 2026-10-09 16:17
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/85da345bf1acc18ca441741e5cf4aa0ed0d69314 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-26wq-p25c-j6fv security-advisories@github.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 06:58 UTC · record ↗