CVE-2026-107296: low-severity vulnerability in mcollina msgpack5
msgpack5: Decoding negative int64 values mutates the input buffer
Published · Updated
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8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 3.7epss 0.3%
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:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected products
mcollina · msgpack5Related CVEs — mcollina msgpack5
In the same product, most dangerous first.
CVE-2021-21368MEDIUMPrototype poisoningEPSS 1.6%CVE-2026-107302HIGHmsgpack5: Truncated map32 headers throw an unexpected errorEPSS 0.5%CVE-2026-107300HIGHmsgpack5: Many buffered values can exhaust the streaming decoder stackEPSS 0.4%CVE-2026-107299MEDIUMmsgpack5: Reserved byte can cause unbounded stream bufferingEPSS 0.4%CVE-2026-107297MEDIUMmsgpack5: Quadratic parsing in the streaming decoderEPSS 0.4%CVE-2026-107298MEDIUMmsgpack5: Deeply nested input can exhaust the decoder stackEPSS 0.4%