Back to overview

CVE-2026-48517

MEDIUM
6.3
CVSS 4.0
Description
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's typeless deserialization includes MessagePackSerializerOptions.ThrowIfDeserializingTypeIsDisallowed(Type) as a safety check for dangerous types. The default implementation checks the outer type name, but it does not recursively inspect array element types or generic type arguments. As a result, a type that would be blocked directly can be wrapped inside an array or constructed generic type and pass the outer type check. The formatter machinery can then materialize formatters for the inner blocked type. This vulnerability is fixed in 2.5.301 and 3.1.7.

Metadata

CVE ID
CVE-2026-48517
State
PUBLISHED
Assigner
GitHub_M
Reserved
2026-05-21 16:18 UTC
Published
2026-06-22 21:03 UTC
Last updated
2026-06-22 21:03 UTC
Primary CWE
CWE-470
CWE-470: Use of Externally-Controlled Input to Select Classe…
Vendor / Product
MessagePack-CSharp / MessagePack-CSharp
Sources
cve.org  ·  NVD

Severity & Metrics

6.3 MEDIUM CVSS 4.0
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products (1)
VendorProductPlatformVersions
MessagePack-CSharp MessagePack-CSharp — >= 3.1.7, < 3.1.7, < 2.5.301
Weakness (CWE)
CWESourceDescription
CWE-470 cna CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
CWE-502 cna CWE-502: Deserialization of Untrusted Data
CVSS scores (1)
ScoreSeverityVersionSourceVector
6.3 MEDIUM 4.0 cna CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
References (1)
Back to overview