SSRF protection

Server-Side Request Forgery (SSRF) is an attack that tricks a server into making HTTP requests to addresses an attacker chooses, such as internal-only targets like localhost, private network ranges, or a cloud provider's metadata endpoint (169.254.169.254). Because workflows can build request URLs from user-controlled input, n8n can guard outbound requests whose destination comes from that input.

SSRF protection is off by default. This page lists the variables that turn it on and tune it.

What protection covers

n8n logs a warning and skips any invalid CIDR range you set in N8N_SSRF_BLOCKED_IP_RANGES or N8N_SSRF_ALLOWED_IP_RANGES, so a typo won't stop the instance from starting.

Blocked by default

When N8N_SSRF_BLOCKED_IP_RANGES includes default, n8n blocks these ranges:

• Private networks (RFC 1918): 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
• Loopback: 127.0.0.0/8, ::1/128
• Link-local, including cloud metadata: 169.254.0.0/16, fe80::/10
• IPv6 unique-local: fc00::/7, fd00::/8
• Reserved or special-purpose: 0.0.0.0/8, 192.0.0.0/24, 192.0.2.0/24, 198.18.0.0/15, 198.51.100.0/24, 203.0.113.0/24

How n8n evaluates a request

n8n checks each destination in this order and stops at the first match:

1. Allowed hostname: if the request hostname matches N8N_SSRF_ALLOWED_HOSTNAMES, n8n allows the request.
2. Blocked hostname: if the request hostname matches N8N_SSRF_BLOCKED_HOSTNAMES, n8n blocks the request. This check runs before DNS resolution, so n8n rejects the name without a lookup, even if it would resolve to a public IP.
3. Allowed IP range: if the resolved IP matches N8N_SSRF_ALLOWED_IP_RANGES, n8n allows the request.
4. Blocked IP range: if the resolved IP matches N8N_SSRF_BLOCKED_IP_RANGES, n8n blocks the request.
5. Otherwise: n8n allows the request.

Because n8n checks the allow lists first, an allow entry always overrides the block list.

Common scenarios

Reach an internal service on purpose. If a workflow must call an internal host, allow just that target rather than turning off protection:

N8N_SSRF_PROTECTION_ENABLED=true
N8N_SSRF_ALLOWED_IP_RANGES=10.20.0.5/32

Allow an internal hostname:

N8N_SSRF_ALLOWED_HOSTNAMES=*.svc.cluster.local

Tighten beyond the defaults. Add ranges specific to your environment:

N8N_SSRF_BLOCKED_IP_RANGES=default,100.64.0.0/10

Deny a hostname by name. Block a host and all its subdomains, regardless of the IP it resolves to:

N8N_SSRF_BLOCKED_HOSTNAMES=example.com,*.example.com

When n8n blocks a request

A request blocked by IP fails with the error "The request was blocked because it resolves to a restricted IP address". A request blocked by hostname fails with "The request was blocked because the destination hostname is restricted". Both descriptions name the target and tell the user to ask their n8n administrator to allow the hostname or IP range. Add the expected target to N8N_SSRF_ALLOWED_IP_RANGES or N8N_SSRF_ALLOWED_HOSTNAMES if the request is genuine.