CVE-2026-107296

low

msgpack5 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, 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

3.7 (CVSS v3.1)

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Severity source: NVD CVSS v3.1 (security-advisories@github.com)

Timeline (UTC)

Published: 2026-10-08 17:17

Modified: 2026-10-14 01:17

NVD status: Deferred

Last synced 3 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)

CWE-471

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/82b70393a824e1088a45a377548d1d9ab82faf91 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-qw35-55vc-rhgj security-advisories@github.com

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 06:58 UTC · record ↗

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