CVEvulnerability

CVE-2026-48502

8.2 HIGH Published 2026-06-22 Modified 2026-06-23 Official page ↗
Status
Analyzed
Published
2026-06-22
Last modified
2026-06-23
Assigner
[email protected]
CVSS 4.0 ([email protected])
8.2 HIGH — 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/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-1188, CWE-125, CWE-190, CWE-407, CWE-409, CWE-470, CWE-502, CWE-674, CWE-789

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.

Affected configurations

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

Related

Weakness · CWE (9)

  • CWE-1188 Initialization of a Resource with an Insecure Default weakness
  • CWE-125 Out-of-bounds Read weakness
  • CWE-190 Integer Overflow or Wraparound weakness
  • CWE-407 Inefficient Algorithmic Complexity weakness
  • CWE-409 Improper Handling of Highly Compressed Data (Data Amplification) weakness
  • CWE-470 Use of Externally-Controlled Input to Select Classes or Code weakness
  • CWE-502 Deserialization of Untrusted Data weakness
  • CWE-674 Uncontrolled Recursion weakness
  • CWE-789 Memory Allocation with Excessive Size Value weakness

References