AIKIDO-2026-255937
MessagePack is vulnerable to Denial of Service (DoS)
63
Medium Risk
This Affects:
MessagePackTL;DR
When LZ4-compressed MessagePack is decompressed, declared uncompressed lengths from the wire are used to allocate output buffers before validating that the compressed data is reasonable. A small payload can claim a very large decompressed size and force large allocations or out-of-memory failures. The fix rejects negative and excessive uncompressed lengths and caps aggregate decompressed size before allocation.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range and use LZ4 compression when deserializing untrusted MessagePack payloads.
Background info
MessagePack is vulnerable to Denial of Service (DoS) in versions 0.0.1 - 2.5.300 and 3.0.0 - 3.1.6.
How to fix this
Upgrade the MessagePack library to the patch version.
Are You Affected?
Connect your repositories to instantly see whether vulnerable or malicious packages exist in your codebase.
Free. No credit card required.
I consent to receiving marketing communications based on Aikido’s Privacy Policy.
SOC 2Compliant
ISO 27001CompliantISO 42001Compliant
FedRAMPImplementing© All Intel data is openly available and commercially licensed.