CVE-2026-57585: CWE-416: Use After Free in msgpack msgpack-python
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.
AI Analysis
Technical Summary
The vulnerability in msgpack-python (CVE-2026-57585) involves an out-of-bounds read triggered by reuse of the Unpacker object after an error has been caught. This use-after-free condition can cause the process to crash with a segmentation fault, leading to denial of service. The flaw affects versions prior to 1.2.1 and has been addressed by fixing the issue in version 1.2.1.
Potential Impact
Exploitation of this vulnerability can cause the affected application to crash, resulting in denial of service. There is no indication of confidentiality or integrity impact. No known exploits are reported in the wild at this time.
Mitigation Recommendations
Upgrade msgpack-python to version 1.2.1 or later, where this vulnerability has been fixed. No other mitigations are specified.
CVE-2026-57585: CWE-416: Use After Free in msgpack msgpack-python
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.
CVSS v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in msgpack-python (CVE-2026-57585) involves an out-of-bounds read triggered by reuse of the Unpacker object after an error has been caught. This use-after-free condition can cause the process to crash with a segmentation fault, leading to denial of service. The flaw affects versions prior to 1.2.1 and has been addressed by fixing the issue in version 1.2.1.
Potential Impact
Exploitation of this vulnerability can cause the affected application to crash, resulting in denial of service. There is no indication of confidentiality or integrity impact. No known exploits are reported in the wild at this time.
Mitigation Recommendations
Upgrade msgpack-python to version 1.2.1 or later, where this vulnerability has been fixed. No other mitigations are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-24T18:49:56.209Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a443df227e9c79719767792
Added to database: 06/30/2026, 22:06:42 UTC
Last enriched: 06/30/2026, 22:21:15 UTC
Last updated: 06/30/2026, 23:37:04 UTC
Views: 4
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