MessagePack is the serializer implementation for Python msgpack.org. Prior to 1.2.3, the msgpack-python C extension (msgpack._cmsgpack) leaks a decoded map value when deserialization rejects a key with strict_map_key=True (the default). Repeated malformed inputs can cause unbound...
Vendor
msgpack vulnerabilities
5 published CVES affecting msgpack, from public sources (CVE.org, NVD, CISA KEV, FIRST EPSS, OSV).
- Total
- 5
- Critical
- 0
- High
- 3
- Medium
- 1
- Low
- 1
- Unscored
- 0
- CISA KEV
- 0
Products
Latest msgpack CVEs
Newest publication first
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HighCVSS 7.5 EPSS 0.54%
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MediumCVSS 5.8
msgpack_unpacker_expand_buffer in src/unpack.c, reached through the public msgpack_unpacker_reserve_buffer API, computes its new buffer size using an unchecked size_t addition of the requested size and the amount already used. The doubling loop guards its own multiplication again...
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CVE-2026-54522 MessagePack::Buffer#clear Use-After-Free that Enables Cross-Buffer Disclosure
PublishedLowCVSS 2.1 PoCMessagePack for Ruby is an implementation of the MessagePack binary serialization format. Prior to 1.8.2, MessagePack::Buffer#clear in ext/msgpack/buffer.c leaves rmem_last, rmem_end, and rmem_owner stale after _msgpack_buffer_shift_chunk returns an rmem page to the shared pool,...
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HighCVSS 7.5
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 w...
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HighCVSS 7.5
MessagePack for Java is a serializer implementation for Java. A denial-of-service vulnerability exists in versions prior to 0.9.11 when deserializing .msgpack files containing EXT32 objects with attacker-controlled payload lengths. While MessagePack-Java parses extension headers...
Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.