VULNERABILITY INTELLIGENCE

CVE-2026-48510

CVSS score7.5 HIGH
EPSS probability0.40%
CISA KEVNot currently listed
Published2026-06-22
Last modified2026-06-25
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, when MessagePack-CSharp decompresses Lz4Block or Lz4BlockArray payloads, it reads declared uncompressed lengths from the wire and allocates output buffers based on those lengths before validating that the compressed data is valid or that the declared expansion is reasonable. A small payload can claim a very large uncompressed length and force a large allocation before LZ4 decoding begins. This vulnerability is fixed in 2.5.301 and 3.1.7.

Weakness classification

  • security-advisories@github.com: CWE-409

Primary references