CVEvulnerability

CVE-2026-48510

6.3 MEDIUM Published 2026-06-22 Modified 2026-06-25 Official page ↗
Status
Analyzed
Published
2026-06-22
Last modified
2026-06-25
Assigner
[email protected]
CVSS 4.0 ([email protected])
6.3 MEDIUM — CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-409, CWE-770

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.

Affected configurations

• messagepack messagepack (< 2.5.301) • messagepack messagepack (>= 3.0.3 < 3.1.7)

Related

Weakness · CWE (2)

  • CWE-409 Improper Handling of Highly Compressed Data (Data Amplification) weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling weakness

References