CVE-2026-57585 Details
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.
A vulnerability in the MessagePack serializer for Python has been identified, allowing for an out-of-bounds read and crash of the Unpacker component. This issue arises when the Unpacker is reused after an error has been caught, potentially leading to a denial-of-service condition. The vulnerability is present in MessagePack versions prior to 1.2.1.
Users should upgrade to MessagePack version 1.2.1, which addresses the vulnerability. Instructions for applying the patch are available on the GitHub advisory page.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 1, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-416 | Use After Free | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| msgpack messagepack | < 1.2.1 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 6, 2026 | Initial Analysis | [email protected] |
| Jul 1, 2026 | CVE Modified | CISA-ADP |
| Jun 30, 2026 | New CVE Received | [email protected] |