CVE-2026-48510
MEDIUM EPSS 14.5%
Published Jun 22, 20261w ago · Modified Jun 23, 20261w ago
6.3 CVSS 4.0
Published Jun 22, 2026 1w ago
Last Modified Jun 23, 2026 1w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
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 Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
14.5% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 2
CWE-409
CWE-770
Affected Products 2
| Vendor | Product | Version | Range |
|---|---|---|---|
| messagepack | messagepack | * | <2.5.301 |
| messagepack | messagepack | * | ≥3.0.3 – <3.1.7 |
References 1
- github.com https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-v72x-2h86-7f8m
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.