Low 3.7Published Oct 8, 2026

CVE-2026-107296msgpack5: Decoding negative int64 values mutates the input buffer

Updated under an hour ago (2026-10-19 09:50 UTC)

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Every CVE for mcollina msgpack5

Exploited in the last 30 days

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: 3.7 LOW (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Weakness (CWE): CWE-471
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

mcollina msgpack5 mcollina:msgpack5 (from the name)	before 6.1.0	CNA record

References

https://github.com/mcollina/msgpack5/security/advisories/GHSA-qw35-55vc-rhgjx-refsource-confirm
https://github.com/mcollina/msgpack5/commit/82b70393a824e1088a45a377548d1d9ab82faf91x-refsource-misc
https://github.com/mcollina/msgpack5/releases/tag/v6.1.0x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.