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Messagepack

4 CVEs product

Monthly

CVE-2026-57585 PyPI HIGH PATCH This Week

Denial of service in the msgpack-python serialization library (versions prior to 1.2.1) lets remote attackers crash a process via an out-of-bounds read when an application reuses an Unpacker instance after a previously raised error was caught. Sending malformed MessagePack data that triggers an error, then feeding further data to the same Unpacker, can drive the process to a SEGV. No public exploit has been identified at time of analysis, and EPSS data was not provided, but the CVSS 3.1 score of 7.5 (availability-only) reflects a straightforward, unauthenticated crash condition.

Memory Corruption Python Use After Free Buffer Overflow Messagepack
NVD GitHub VulDB
CVSS 3.1
7.5
EPSS
0.3%
CVE-2026-21452 Maven HIGH POC PATCH This Week

MessagePack for Java versions prior to 0.9.11 are vulnerable to denial-of-service attacks through malicious .msgpack files that exploit unbounded heap allocation when deserializing EXT32 objects. An unauthenticated attacker can craft a small payload with attacker-controlled extension lengths that causes the library to attempt allocating excessive memory, leading to JVM heap exhaustion and service unavailability. Public exploit code exists for this vulnerability; organizations using affected versions should update immediately.

Java Deserialization Messagepack
NVD GitHub
CVSS 3.1
7.5
EPSS
0.0%
CVE-2022-41719 Go HIGH POC PATCH This Week

Unmarshal can panic on some inputs, possibly allowing for denial of service attacks. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Denial Of Service Messagepack
NVD GitHub
CVSS 3.1
7.5
EPSS
1.0%
CVE-2020-5234 NuGet MEDIUM PATCH This Month

MessagePack for C# and Unity before version 1.9.11 and 2.1.90 has a vulnerability where untrusted data can lead to DoS attack due to hash collisions and stack overflow. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity.

Buffer Overflow Stack Overflow Messagepack
NVD GitHub
CVSS 3.1
6.5
EPSS
1.6%
EPSS 0% CVSS 7.5
HIGH PATCH This Week

Denial of service in the msgpack-python serialization library (versions prior to 1.2.1) lets remote attackers crash a process via an out-of-bounds read when an application reuses an Unpacker instance after a previously raised error was caught. Sending malformed MessagePack data that triggers an error, then feeding further data to the same Unpacker, can drive the process to a SEGV. No public exploit has been identified at time of analysis, and EPSS data was not provided, but the CVSS 3.1 score of 7.5 (availability-only) reflects a straightforward, unauthenticated crash condition.

Memory Corruption Python Use After Free +2
NVD GitHub VulDB
EPSS 0% CVSS 7.5
HIGH POC PATCH This Week

MessagePack for Java versions prior to 0.9.11 are vulnerable to denial-of-service attacks through malicious .msgpack files that exploit unbounded heap allocation when deserializing EXT32 objects. An unauthenticated attacker can craft a small payload with attacker-controlled extension lengths that causes the library to attempt allocating excessive memory, leading to JVM heap exhaustion and service unavailability. Public exploit code exists for this vulnerability; organizations using affected versions should update immediately.

Java Deserialization Messagepack
NVD GitHub
EPSS 1% CVSS 7.5
HIGH POC PATCH This Week

Unmarshal can panic on some inputs, possibly allowing for denial of service attacks. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Denial Of Service Messagepack
NVD GitHub
EPSS 2% CVSS 6.5
MEDIUM PATCH This Month

MessagePack for C# and Unity before version 1.9.11 and 2.1.90 has a vulnerability where untrusted data can lead to DoS attack due to hash collisions and stack overflow. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity.

Buffer Overflow Stack Overflow Messagepack
NVD GitHub

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