Port 5883JUTE (JavaScript Unit Test Environment)

Port 5883 is assigned to JUTE, the JavaScript Unit Test Environment.

transport: tcp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

Technical Details

what runs on :5883

JUTE (JavaScript Unit Test Environment) is registered on port :5883 over tcp to Mark Ethan Trostler, assigned November 2011. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :5883

this machine

# linux
sudo ss -tlpn 'sport = :5883'

# macos / bsd
sudo lsof -nP -i :5883

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :5883

another host

nmap -sV -p T:5883 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :5883

risk score

1/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :5883 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

Record

iana registry entry

port: :5883
service: JUTE (JavaScript Unit Test Environment)
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA assigns TCP port 5883 to the JavaScript Unit Test Environment (JUTE). The assignment is registered to Mark Ethan Trostler; no widely established deployment or common listener is known.
lookups: 0rank 993
added: 2026-10-09
updated: 2026-10-09
references: IANA service name registry — port 5883

Something wrong?

This record is maintained by the engineers who use port 5883. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-10-09.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

browse categories →

ports registered around :5883, by lookups.

port	service	proto	category	risk	views
:5938	TeamViewer	TCPUDP	Remote Access	caution	65.0k
:5900	VNC Remote Desktop	TCPUDP	Remote Access	caution	14.2k
:5852	Adeona OpenDHT Client	TCP	Security	caution	9.3k
:5912	Tidal Scheduler Agent	TCP	System	caution	8.5k
:5850	COMIT SE PCR	TCP	Network Services	caution	4.2k
:5859	WHEREHOO	TCPUDP	—	safe	0
:5904	Air-Ground SWIM	TCPUDPSCTP	Network Services	safe	0
:5910	Context Management	SCTP	System	safe	0

risk mix of the 8 listed

safe38%
caution63%

0 of 8 encrypted

Port :5883JUTE (JavaScript Unit Test Environment)

Technical Details

Security Information

Related Ports

Port 5883JUTE (JavaScript Unit Test Environment)