Port 27018MongoDB Shard Server

MongoDB shard servers commonly listen on TCP port 27018 by default.

transport: tcp
in transit: cleartext
assignment: unofficial
risk: 8/10
lookups: 0

Technical Details

what runs on :27018

MongoDB's client and cluster communication uses its MongoDB wire protocol over TCP, with BSON documents exchanged in framed messages. Drivers begin a connection by negotiating server capabilities with a hello command; TLS can be configured but is not enabled by default. In a typical sharded cluster, mongos listens on 27017 and config-server mongod instances use 27019 by default.

Security Information

exposure of :27018

risk score

8/ 10risk

treat as sensitive. widely scanned and regularly exploited when reachable — restrict it to known sources.

databases averages 3.8 across 148 ports — this one sits 4.2 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

unofficial

used by convention, not registered — what answers here varies by deployment

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

This port exposes a database service and should not be reachable from the public internet. If accessible, an attacker may probe the MongoDB protocol and, depending on authentication and network configuration, access or alter data; restrict it to trusted cluster and administrative networks and configure authentication and TLS.

Record

iana registry entry

port: :27018
service: MongoDB Shard Server
transport: TCP
encryption: cleartext
assignment: convention only
risk: 8/10risk
category: Databases
usage: MongoDB uses TCP port 27018 as the default for a `mongod` instance started with the `--shardsvr` option. Engineers commonly encounter it on the shard members of a MongoDB sharded cluster; deployments can configure a different port.
lookups: 0rank 993
added: 2026-10-08
updated: 2026-10-08
references: MongoDB Default MongoDB Port
MongoDB Wire Protocol

Something wrong?

This record is maintained by the engineers who use port 27018. 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 2026-10-08.

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edit this record →back to the registry

Related Ports

all 148 in databases →

the 8 most looked-up other ports in databases — 148 ports carry that label.

port	service	proto	category	risk	views
:8882	Atlasz Secure App Server	TCP	Web Services	caution	66.9k
:9001	ETL Service Manager	TCPUDP	Databases	caution	28.6k
:2484	Oracle SSL Listener	TCPUDPtls	Security	caution	25.0k
:5495	Applix TM1 Admin	TCP	Databases	caution	24.8k
:591	FileMaker Web Sharing	TCP	Web Services	caution	23.1k
:1521	Oracle TNS Listener	TCP	Security	caution	19.6k
:21001	AMLFilter Admin	TCP	Security	caution	19.2k
:18206	Audition FAM DB	TCPUDP	Databases	caution	19.1k

risk mix of the 8 listed

caution100%

1 of 8 encrypted

Port :27018MongoDB Shard Server

Technical Details

Security Information

Related Ports

Port 27018MongoDB Shard Server