CVE-2026-57585
MessagePack: Out-of-bounds read/crash on Unpacker reuse after caught error
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
MessagePack is the serializer implementation for Python msgpack.org. Prior to 1.2.1, there is an Out-of-bounds read/crash on Unpacker reuse after a caught error, potentially leading to a DoS attack. If the Unpacker is used repeatedly after an error occurs, the process may crash with a SEGV. This issue has been fixed in version 1.2.1.
| CWE | CWE-416 |
| Vendor | msgpack |
| Product | msgpack-python |
| Published | Jun 30, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
msgpack / msgpack-python
< 1.2.1