CVE-2026-48502
8.2
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/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:XShow more
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:XShow less
Source: security-advisories@github.com (Secondary)
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 (2)
Products: Messagepack: Messagepack
Configuration A
| Vulnerable Software | Affected Versions |
|---|---|
| Before 2.5.301 |
Related CWEs
CWE-1188
Initialization of a Resource with an Insecure Default
The product initializes or sets a resource with a default that is intended to be changed by the administrator, but the default is not secure.
CWE-125
Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
CWE-190
Integer Overflow or Wraparound
The product performs a calculation that can
produce an integer overflow or wraparound when the logic
assumes that the resulting value will always be larger than
the original value. This occurs when an integer value is
incremented to a value that is too large to store in the
associated representation. When this occurs, the value may
become a very small or negative number.
CWE-407
Inefficient Algorithmic Complexity
An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
CWE-409
Improper Handling of Highly Compressed Data (Data Amplification)
The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.
CWE-470
Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
The product uses external input with reflection to select which classes or code to use, but it does not sufficiently prevent the input from selecting improper classes or code.
CWE-502
Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
CWE-674
Uncontrolled Recursion
The product does not properly control the amount of recursion that takes place, consuming excessive resources, such as allocated memory or the program stack.
CWE-789
Memory Allocation with Excessive Size Value
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
References (1)
Source: security-advisories@github.com
MitigationVendor Advisory
Timeline
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