U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-48502 Detail

Description

MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePackReader.ReadDateTime() can allocate stack memory based on an attacker-controlled MessagePack extension length. In the slow path for timestamp extension parsing, the computed tokenSize includes the extension body length from the wire and is used in a stackalloc operation before the extension length is validated as one of the valid timestamp sizes. A very small payload can claim a large timestamp extension body and cause a stack allocation large enough to trigger an uncatchable StackOverflowException, terminating the host process. This vulnerability is fixed in 2.5.301 and 3.1.7.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-B 8.2 HIGH
Vector:  CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to [email protected].

URL Source(s) Tag(s)
https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-382j-8mxh-c7x2 GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-125 Out-of-bounds Read GitHub, Inc.  
CWE-190 Integer Overflow or Wraparound GitHub, Inc.  
CWE-407 Inefficient Algorithmic Complexity GitHub, Inc.  
CWE-409 Improper Handling of Highly Compressed Data (Data Amplification) GitHub, Inc.  
CWE-470 Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') GitHub, Inc.  
CWE-502 Deserialization of Untrusted Data GitHub, Inc.  
CWE-674 Uncontrolled Recursion GitHub, Inc.  
CWE-789 Memory Allocation with Excessive Size Value GitHub, Inc.  
CWE-1188 Insecure Default Initialization of Resource GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-48502
NVD Published Date:
06/22/2026
NVD Last Modified:
06/22/2026
Source:
GitHub, Inc.