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Security report for klaviyo.com

Klaviyo · Technology · United States

Medium risk. 2 critical or high findings in SSL/TLS and Security headers.

Security score

67/100

Risk levelMedium

0–100, higher is better. How it is calculated

Klaviyo is a leading SaaS marketing platform specializing in CRM solutions for consumer brands, integrating email marketing, SMS, and a customer data platform to enable personalized and scalable customer engagement. The company targets e-commerce and consumer brand businesses, positioning itself as a key player in marketing automation technology. The website reflects a mature digital infrastructure, leveraging modern frameworks like Gatsby and React, and integrates multiple analytics and marketing tools such as Google Tag Manager, HubSpot, and Optimizely. Security posture is strong with HTTPS enforcement, security headers, and anti-bot measures like reCAPTCHA, although explicit security policies and incident response information are not publicly detailed. Overall, the site is professional, well-structured, and privacy-conscious, though the absence of WHOIS data introduces some uncertainty in domain legitimacy. Strategic recommendations include publishing detailed security and incident response policies and establishing a vulnerability disclosure program to enhance trust and compliance.

Scanned

This is an earlier scan of klaviyo.com. View the latest report

NIS2 and GDPR posture

GDPR outside view
88/ 100 · Low
Checks completed
7of 7

NIS2 Art. 21(2)

  1. (a) Risk analysis and security policies: Not visible from outside
  2. (b) Incident handling: One indicator
  3. (c) Business continuity, backups and crisis management: Not visible from outside
  4. (d) Supply chain security: Not visible from outside
  5. (e) Secure acquisition, development and maintenance, including vulnerability handling: Partly checked
  6. (f) Assessing the effectiveness of security measures: Not visible from outside
  7. (g) Cyber hygiene and security training: Not visible from outside
  8. (h) Cryptography and encryption: Partly checked
  9. (i) HR security, access control and asset management: One indicator
  10. (j) Multi-factor authentication and secured communications: Not visible from outside

This scan rated NIS2 with an earlier keyword method that is no longer shown; rescan for the per-article view. Risk management, continuity, supply chain, training, MFA, management oversight (Art. 20) and incident reporting (Art. 23) need internal evidence, and Guard cannot tell whether NIS2 applies to this organisation.

GDPR is indicative only, based on publicly visible signals: Articles 7, 12, 13 and 32 of Regulation (EU) 2016/679 and Article 5(3) of the ePrivacy Directive. Not a certification or legal assessment.

Priority findings

2 findings rated critical or high. Fix these first.

  1. SSL/TLS

    TLS encrypts the connection and proves the site is really yours. Weak or expiring certificates trigger browser warnings and put traffic at risk.

    • Critical

      Unable to retrieve SSL certificate

      Could not establish secure connection to retrieve certificate information

      What to do: Check if the server is accessible and SSL/TLS is properly configured

  2. Security headers

    Security headers are instructions your web server sends to every visitor’s browser. Missing ones leave visitors more exposed to attacks such as clickjacking and injected scripts.

    • High

      Missing Content-Security-Policy header

      Controls resources the browser is allowed to load

      What to do: Implement a Content-Security-Policy appropriate for your application

      • ASVS V3.4.3
      • OWASP Secure Headers: OWASP Secure Headers Project recommends Content-Security-Policy: default-src 'self'; form-action 'self'; base-uri 'self'; object-src 'none';…

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Keep watching klaviyo.com

This scan found 15 issues across 6 checks. Monitoring re-runs those checks daily, emails you when something material changes and records each fix, so you can show progress.

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  • TLS certificates and expiry
  • DNS records
  • SPF, DKIM and DMARC
  • Security headers
  • GDPR and NIS2 posture
  • Exposed services
  • Third-party trackers
  • Security score drift

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Results by check

Each check with its score, findings and the evidence it collected.

How this score is calculated

The security score runs 0–100, higher is better. It is the plain average of the security checks that completed in this scan, each counted equally. A check that could not run is left out: it counts neither as a pass nor as a fail.

Counted in this score

SSL/TLS
0
Security headers
65
Email security
65
DNS health
85
Network security
100
GDPR outside view
88
Average
67

Not counted

  • NIS2 outside view: Re-weights evidence from the TLS, email, DNS, network and hygiene checks, so counting it would count that evidence twice. Shown on its own.
  • OffSeq Observations: An AI reading of the site, useful context but not reproducible evidence. Shown on its own.

Findings that cap the score at 49

Each of these is serious on its own, so while any is present the site cannot rate better than high risk, however good the other checks are.

  • The certificate is not trusted by browsers
  • The website is not served over HTTPS
  • A database, remote desktop, file-sharing or Telnet service is reachable from the internet
  • The page loads a script from a compromised source
  • The domain registration has expired
  • SPF authorises every server to send mail as the domain

Partial scans

When the site blocks Guard or most checks cannot run, the score covers only the checks that ran (usually DNS and email), is capped at 75 and is shown as partial, without a risk level.

Risk levels

  • Critical0–25
  • High26–49
  • Medium50–75
  • Low76–100

Technical appendix

Business context, site observations and technical notes gathered during the scan, and the standards behind each reference.

Business context

Business profile

Klaviyo operates in the technology and e-commerce sectors, offering a SaaS CRM platform that combines email and SMS marketing with a customer data platform. Its business model focuses on subscription-based services for consumer brands seeking personalized marketing solutions. The company enjoys a strong market position with a professional online presence and integration with major marketing and analytics platforms. The target audience includes medium to large consumer brands and e-commerce businesses. The website's content quality and branding consistency support a high level of business credibility. While no parent or subsidiary companies are identified, the company maintains active social media channels and uses trusted third-party services for marketing and analytics.

Security posture

The website demonstrates a high security maturity level with HTTPS enforced, comprehensive security headers, and use of reCAPTCHA to protect forms. No exposed sensitive data or vulnerable libraries were detected in the analyzed content. However, the lack of publicly available security policies, incident response contacts, and vulnerability disclosure mechanisms indicates room for improvement in transparency and readiness. Compliance with GDPR is indicated through privacy and cookie policies with consent mechanisms. The security score is strong but could be enhanced by publishing explicit security governance documents and providing direct security contact channels.

Recommendations

  1. Publish a detailed security policy and incident response plan on the website.
  2. Implement and publicize a vulnerability disclosure program or security.txt file.
  3. Provide clear contact information for security incidents, such as a security@ or abuse@ email address.
  4. Regularly audit and update third-party scripts and libraries to mitigate vulnerabilities.
  5. Enhance transparency around data protection officer contact and data retention policies.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Klaviyo
Description
Klaviyo is a CRM platform for consumer brands combining email marketing and SMS with an embedded Customer Data Platform (CDP) to unify data for personalized, scalable customer engagement.
Key services
Email marketing, SMS marketing, Customer Data Platform (CDP), Personalized customer engagement
Content quality
excellent
Branding
consistent

Technology

Stack
Gatsby, React, Google Tag Manager, Bing Ads, HubSpot Analytics, Cloudfront CDN, Optimizely, Google reCAPTCHA
Frameworks
Gatsby
Platforms
Netlify
Performance
fast
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
90/100
Good practices seen
  • HTTPS enforced
  • Use of reCAPTCHA for forms
  • Cookie consent banner implemented
  • No exposed sensitive data in HTML

Analytics and tracking

Services
Google Analytics (via GTM), HubSpot Analytics, Bing Ads
Tracking level
moderate
Privacy practices
good

Advertising

Ad networks
Bing Ads
Tracking pixels
HubSpot Analytics, Optimizely
Marketing tools
HubSpot, Optimizely
Transparency
good

Site quality

Design
excellent
User experience
excellent
Content relevance
excellent
Navigation
excellent
Professionalism
excellent
Trustworthiness
high

Key observations

  1. Website is fully accessible with rich content and professional design.
  2. No WAF or blocking mechanisms detected.
  3. WHOIS data is missing, which is unusual for a commercial domain.
  4. Strong privacy and cookie policies with consent mechanisms are present.
  5. No direct company contact emails or phone numbers found in the HTML content provided.
  6. Social media presence confirmed via Facebook link.
  7. Multiple modern marketing and analytics tools are integrated.
  8. Security headers and HTTPS are properly implemented.
  9. No vulnerabilities or exposed sensitive data detected in the HTML content.
Technical notes

Notes

The website is built using modern web technologies including Gatsby and React, hosted likely on Netlify, ensuring fast performance and excellent mobile optimization. Integration with Google Tag Manager, HubSpot, Bing Ads, and Optimizely indicates a mature marketing technology stack. The site uses standard security best practices such as HTTPS and security headers. Accessibility and SEO optimizations are well implemented. No technical debt or major performance issues were detected in the provided content. Opportunities exist to improve technical documentation related to security and compliance to further strengthen the platform's trustworthiness.
Standards and sources

Reference chips under each finding point to the standard, regulation or specification the finding relates to. They are taken from the official datasets below and mapped conservatively: a finding with no defensible link shows none. NIS2 and GDPR references mark where a finding is relevant evidence, not a compliance verdict. Implementing Regulation (EU) 2024/2690 binds digital infrastructure and digital service providers; for other entities it is the most detailed public reading of the Article 21 measures. WCAG, EN 301 549, European Accessibility Act and Web Accessibility Directive references name the requirement an automated accessibility rule relates to; they are not a conformance verdict.

Retrieved 2026-10-25

Earlier scans of this domain

  1. 78/100 −1Low26 findingsView report
  2. 79/100 +3Low25 findingsView report
  3. 76/100Low23 findingsView report
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