Port 11434Ollama API

Port 11434 (TCP) is the Ollama API. By default Ollama binds 127.0.0.1:11434 with no built-in authentication, which is why a Docker container, WSL or another machine gets "connection refused". Reach it from a container with host.docker.internal, or set OLLAMA_HOST to listen more widely, with an authenticated proxy in front. Update to 0.17.1 or later for CVE-2026-7482.

inWeb Services System

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

Technical Details

what runs on :11434

This is an HTTP API over TCP, normally bound to localhost:11434. Clients send HTTP requests to endpoints such as /api/generate, /api/chat, /api/tags, and /api/pull; responses may be streamed as newline-delimited JSON. Ollama does not use TLS by default, although deployments can place it behind a TLS-terminating proxy.

Connection refused on 11434

Is it running? Start ollama serve or the desktop app. "Address already in use" means another copy is already running.
From a Docker container: localhost is the container itself. Use http://host.docker.internal:11434; on Linux, add --add-host=host.docker.internal:host-gateway to the container.
From WSL2 or another machine: Ollama listens only on loopback. Set OLLAMA_HOST=0.0.0.0:11434 on the host, restart Ollama and allow the port through the host firewall. Do this only on a network you trust.

Security Information

exposure of :11434

risk score

8/ 10risk

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

web services averages 3.1 across 243 ports — this one sits 4.9 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

The local API does not generally require authentication, so exposing it beyond a trusted host or network can permit unauthenticated model inference, model downloads, and other API operations. Internet exposure can enable resource exhaustion, unauthorized use of downloaded models, and potentially dangerous interactions with host-integrated workflows; it should normally remain localhost-only or be protected by an authenticated reverse proxy.

Known vulnerabilities

CVE-2026-7482 ("Bleeding Llama"): an unauthenticated heap over-read through /api/create can leak process memory, including environment variables, API keys and conversation data. Fixed in 0.17.1.
CVE-2024-37032 ("Probllama"): remote code execution through path traversal. Fixed in 0.1.34.

Record

iana registry entry

port: :11434
service: Ollama API
transport: TCP
encryption: cleartext
assignment: convention only
risk: 8/10risk
category: Web Services System
usage: Ollama listens on TCP port 11434 by default for its local API. Engineers encounter it on developer workstations, AI inference hosts, and applications using Ollama for local model serving.
lookups: 0rank 993
added: 2026-08-19
updated: 2026-10-17
references: IANA Service Name and Transport Protocol Port Number Registry
Ollama API documentation
Ollama FAQ

Something wrong?

This record is maintained by the engineers who use port 11434. 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 2026-10-17.

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

all 243 in web services →

the 8 most looked-up other ports in web services — 243 ports carry that label.

port	service	proto	category	risk	views
:8888	Sun Answerbook & Alt HTTP	TCP	Web Services	caution	123.9k
:8000	Intel Remote Desktop / Alternate HTTP Port	TCP	Web Services	safe	84.3k
:8888	NewsEDGE	TCPUDP	Web Services	caution	83.3k
:8888	HTTP Alternative Port	TCP	Web Services	caution	76.5k
:8888	GNUmp3d Streaming HTTP	TCP	Web Services	caution	76.3k
:9080	Groove RPC	TCPUDP	Web Services	caution	70.8k
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:80	HTTP	TCPUDP	Web Services	caution	67.3k

risk mix of the 8 listed

safe13%
caution88%

0 of 8 encrypted

Port :11434Ollama API