CVE-2026-57585

MessagePack: Out-of-bounds read/crash on Unpacker reuse after caught error

Published Jun 30, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Msgpack
Msgpack msgpack-python
Vendors & Products Msgpack
Msgpack msgpack-python
Type Values Removed Values Added
Description 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.
Title MessagePack: Out-of-bounds read/crash on Unpacker reuse after caught error
Weaknesses CWE-416
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 1, 2026, 2:54 PM
Reserved
Jun 24, 2026, 6:49 PM
Status
Analyzed
Published
Jun 30, 2026, 10:16 PM
Modified
Oct 25, 2026, 9:10 PM