Penetration Testing Squarespace Sites — What UK Businesses Should Know

Squarespace Looks Polished. But Is It Secure?

Squarespace is a favourite for UK creative businesses, portfolio sites, and professional services firms. The templates are excellent, the interface is clean, and getting online takes hours rather than weeks. But a well-designed website isn't the same as a secure one — and if your Squarespace site collects personal data, processes bookings, or connects to any external service, you have security obligations you may not be meeting.

This guide covers what a penetration test checks on a Squarespace site, what the actual risks look like, and what UK businesses should do about them.

What Squarespace Controls vs. What You Control

Squarespace handles its own server infrastructure, database security, and core platform patching. You don't get root access to a Squarespace server, and you don't need to worry about operating system vulnerabilities. Squarespace's security team handles that.

But the layer you do control — the integrations you connect, the code blocks you add, the third-party services you embed, the form data you collect — is entirely your responsibility. That's also where most of the risk lives.

Real Security Risks on Squarespace Sites

Third-Party Scripts and Integrations

Every third-party service you embed on a Squarespace site — analytics tools, live chat widgets, booking systems, social media pixels, payment processors — loads external JavaScript that executes in your visitors' browsers. Each one is a potential attack vector.

Security scans inventory every external script origin loading on your pages. If a third-party service you're using gets compromised, that malicious code runs on your site too. Regular audits of what's loading — and from where — are basic hygiene.

Custom Code Blocks and Injected Scripts

Squarespace allows code injection in headers and footers, and custom code blocks within pages. These are common places where developers (or business owners following online tutorials) accidentally introduce vulnerabilities. Hardcoded API keys in JavaScript code blocks are a particularly common finding — any visitor can read them in the page source.

A security scan specifically looks for credentials and API keys exposed in client-side code.

Security Header Configuration

HTTP security headers are your first line of browser-level defence. Missing or misconfigured headers leave visitors exposed to clickjacking, cross-site scripting, and information disclosure. Squarespace doesn't give you full control over all HTTP headers, but there are headers you can influence — and a security scan will tell you exactly what's missing and what's correctly set.

DNS and Email Authentication

Your domain's DNS records include SPF, DKIM, and DMARC entries that protect against email spoofing. Without them, attackers can send emails that appear to come from your domain — used in phishing attacks against your customers. A comprehensive security scan always includes DNS email authentication checks, regardless of what website platform you're using.

Form Data and Privacy Compliance

Squarespace forms are easy to set up, but how you handle the data matters enormously under UK GDPR. Are form submissions going to a secure location? Are you retaining data longer than necessary? Are you collecting more information than you need? A security review considers not just the technical configuration but whether your data handling practices expose you to compliance risk.

Connected E-Commerce and Payment Processing

If you're using Squarespace Commerce, payment processing happens through Squarespace's own integration or third-party processors like Stripe. The payment flow itself is typically secure — but the configuration around it, including checkout redirects, SSL configuration on your domain, and how order data is stored, is worth auditing.

UK GDPR and Squarespace

Squarespace stores data on servers that may be outside the UK and EU. If you're collecting personal data from UK residents, you need to understand where that data goes and ensure your use of Squarespace complies with UK GDPR transfer rules. This includes reviewing Squarespace's Data Processing Agreement and ensuring you have the appropriate legal basis for any data you collect.

Beyond platform compliance, you're responsible for any personal data you collect through your forms, your integrations, and your own custom code. A data breach on a Squarespace site — even one caused by a third-party integration you installed — is your breach to report to the ICO.

What a Security Scan Covers for Squarespace

Yrzo AI's Essential scan is built specifically for hosted platforms like Squarespace, Wix, and Shopify. Rather than running checks that only apply to custom-built applications, it focuses on the actual attack surface of a hosted site.

For Squarespace sites, that means SSL/TLS configuration, security header analysis, DNS and email authentication checks (SPF, DKIM, DMARC), third-party script inventory and origin analysis, exposed credentials in client-side code, and data exposure checks including indexed pages that shouldn't be public.

You get a full PDF report with findings rated by severity and plain-English remediation guidance. No security background required to act on it.

The Practical Takeaway

Squarespace is a solid platform and its core infrastructure is well-maintained. But your Squarespace site is not automatically secure just because you're on Squarespace. The integrations you add, the code you inject, the data you collect, and the DNS records your domain uses are all your responsibility — and they're all things that can and do go wrong.

A periodic security scan is the most efficient way to find out where your gaps are and close them before someone else finds them first.