CVE-2026-48506
Description
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePackReader.TrySkip() recursively descends into nested arrays and maps without incrementing the reader depth or calling the configured depth checks. This bypasses MessagePackSecurity.MaximumObjectGraphDepth, the library's documented protection against deeply nested object graphs. Many generated and dynamic formatters call reader.Skip() when they encounter unknown map keys, unknown array members, ignored fields, or data that should be skipped for forward compatibility. A deeply nested value in one of these skipped positions can therefore cause unbounded recursion and an uncatchable StackOverflowException. This vulnerability is fixed in 2.5.301 and 3.1.7.
How to fix
- messagepack messagepack2.5.301, 3.1.7 or later
- MessagePack2.5.301, 3.1.7 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| messagepack messagepack | v < 2.5.301, 3.0.3 ≤ v < 3.1.7 | 2.5.301, 3.1.7 |
| MessagePackNuGet | v < 2.5.301, 3.0 ≤ v < 3.1.7 | 2.5.301, 3.1.7 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.