I'm not 100% sure it is a Noesis bug, but it looks very suspicious.
Recently I catched a couple of "read access violation" crashes during memcpy part of D3D12RenderDevice::UploadUniforms

        uint32_t size = Align(data.numDwords * sizeof(uint32_t), 256);
        void* ptr = MapBuffer(mConstants[i], size);
        memcpy(ptr, data.values, size);

I didn't save exact values, but I can definitely say:

• data->numDwords was 7;
• data->values was not null, but seemingly a valid value;
• access violation happened at 4096 byte boundary (last digits were 000 in hex);
• the difference between the faulted address and data.values was exactly 240 bytes.

I can try to get more data when it happens next time, but it is very rare.
So far it just looks like memcpy reading beyond the input buffer. Shouldn't it be copying "numDwords * 4" instead of "size" bytes?