CVE-2026-107296
msgpack5: Decoding negative int64 values mutates the input buffer
CVSS Score
3.7
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-471 |
| Vendor | mcollina |
| Product | msgpack5 |
| Published | Oct 8, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Affected Versions
mcollina / msgpack5
< 6.1.0