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JsonConvert.DeserializeObject can throw several unexpected exceptions #1947
Description
JsonConvert.DeserializeObject can throw several unexpected exceptions (JsonReaderException is the one that is usually expected). These are:
- ArgumentException
- JsonSerializationException
- JsonWriterException
- NullReferenceException
Documentation doesn't say anything about this, but deserialization is definitely weird place for a JsonWriterException. ArgumentException and NullReferenceException should not be possible in my opinion (if the input strings are non-empty). Here is the complete program to reproduce all of this:
using System;
namespace Newtonsoft.Json.Run
{
public class Program
{
public static void Main(string[] args)
{
try
{
JsonConvert.DeserializeObject("[{\"click\":\"X\",\"Close()\"://[{\"click\":\"Kpen()\"},{\"cOOOOOOOOOO\u007f]}}}");
}
catch (ArgumentException) { }
try
{
JsonConvert.DeserializeObject("{\"menu\":{\"id\":1,\"val\":\"X\",\"pop\":{\"a\":[{\"click\":\"Open()\"},{\"click\":\"Close()\"}]}}");
}
catch (JsonSerializationException) { }
try
{
JsonConvert.DeserializeObject("{\"menu\":{\"id\":1,\"val\":\"X\",\"pop\":{\"a\":[{\"clicT\":\"Open()\"},");
}
catch (JsonWriterException) { }
try
{
JsonConvert.DeserializeObject("[new\0([");
}
catch (NullReferenceException) { }
}
}
}Found via SharpFuzz.
Activity
AaronJThompson commentedon Nov 10, 2021
The last 3 seem to have been fixed. However, the first one now throws the error:
Can not add Newtonsoft.Json.Linq.JValue to Newtonsoft.Json.Linq.JObject.Which I presume is still a bug
Aws-amplify-cli-puppy commentedon Oct 14, 2025
https://linebackersudoku.github.io/unsophisticated73/