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Security report for klaviyo.com

Klaviyo, Inc. · Technology · United States

Low risk. 5 critical or high findings in Security headers and GDPR outside view.

Security score

76/100

Risk levelLow

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

Klaviyo, Inc. is a leading enterprise-level technology company specializing in B2C CRM and marketing automation solutions. Their platform integrates email marketing, SMS, mobile app marketing, and customer data platform capabilities to enable consumer brands to deliver personalized and scalable customer engagement. The company maintains a strong market position with a comprehensive suite of services tailored for consumer brands, supported by a robust integration ecosystem and advanced AI capabilities. Technically, Klaviyo employs modern web technologies including React and Gatsby, hosted on Cloudflare and Netlify infrastructure, ensuring fast performance and excellent mobile optimization. The site leverages advanced analytics tools such as Google Analytics 4 and Optimizely for user tracking and experimentation, with a well-implemented consent mechanism via OneTrust. From a security perspective, Klaviyo demonstrates good practices with multiple security headers and certifications like ISO 27001 and SOC 2. However, the SSL certificate is currently invalid, and some advanced TLS features are not enabled, indicating areas for improvement. No explicit vulnerability disclosure or security.txt was found, and no direct contact for a data protection officer was identified. Overall, Klaviyo presents a mature digital presence with strong business and technical foundations. Addressing SSL and advanced security configurations will enhance their security posture and trustworthiness further.

Scanned

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

NIS2 and GDPR posture

GDPR outside view
25/ 100 · Critical
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

5 findings rated critical or high. Fix these first.

  1. 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';…

  2. GDPR outside view

    These are the privacy signals visitors and data protection authorities look for under GDPR.

    • High

      No Privacy Policy found

      GDPR requires a clear and accessible privacy policy

      What to do: Add a comprehensive privacy policy page and link to it prominently

    • High

      No Cookie Policy found

      GDPR requires clear information about cookie usage

      What to do: Add a dedicated cookie policy explaining cookie usage and purposes

    • High

      No Cookie Consent Banner found

      GDPR requires explicit consent for non-essential cookies

      What to do: Implement a cookie consent banner that appears on first visit

    • High

      Third-party services without privacy policy

      Detected services: Google Analytics, Facebook, Twitter, LinkedIn, Google APIs

      What to do: Document all third-party data sharing in your privacy policy

Need hands-on remediation? Email guard@offseq.com

Keep watching klaviyo.com

This scan found 16 issues across 5 checks. Monitoring re-runs those checks daily, emails you when something material changes and records each fix, so you can show progress.

Daily monitoring

Recommended

€25per month

  • 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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Full report

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Prices incl. 21% VAT. Secure checkout by Mollie; sold by SEQ SIA, Latvia.

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
100
Security headers
65
Email security
80
DNS health
85
Network security
100
GDPR outside view
25
Average
76

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 sector with a focus on e-commerce and consumer brand marketing. Their business model is SaaS-based, offering a unified platform that combines marketing automation, customer data management, and analytics. The company targets consumer brands seeking to enhance customer relationships through personalized marketing across multiple channels. Their extensive integration network and AI-driven tools provide competitive advantages, enabling smarter marketing decisions and scalable growth. The presence of a dedicated developer portal and partner ecosystem indicates a strategic emphasis on extensibility and collaboration. Klaviyo's content and resource offerings, including blogs, case studies, and educational materials, support customer engagement and market leadership.

Security posture

Klaviyo's security posture is solid, supported by recognized certifications such as ISO 27001 and SOC 2, which reflect adherence to industry best practices. The website employs essential security headers like HSTS, X-Content-Type-Options, X-Frame-Options, and X-XSS-Protection, enhancing protection against common web vulnerabilities. However, the SSL certificate is currently invalid, and no support for modern TLS protocols (TLS 1.2 or 1.3) was detected, which is a critical security gap. The absence of OCSP stapling and session resumption mechanisms further indicates opportunities for strengthening SSL/TLS configurations. No public vulnerability disclosure policy or security.txt file was found, and no direct incident response contact channels were identified, which may impact transparency and responsiveness. Overall, while foundational security controls are in place, addressing these gaps is essential to maintain a robust security posture.

Recommendations

  1. Renew and properly configure the SSL certificate to enable valid HTTPS connections with support for TLS 1.2 or higher.
  2. Implement OCSP stapling and enable session resumption to improve SSL/TLS performance and security.
  3. Publish a vulnerability disclosure policy and security.txt file to enhance transparency and facilitate responsible reporting.
  4. Establish and publicize incident response contact channels to improve security incident management and communication.
  5. Regularly review and update security headers and configurations to align with evolving best practices and compliance requirements.

Contact details published on the site

Addresses
Legal name
Klaviyo, Inc.
Technical notes

Notes

The website is built using modern JavaScript frameworks including React and Gatsby, indicating a high level of technical maturity and focus on performance. Hosting is provided by Cloudflare and Netlify, leveraging CDN and edge caching for fast content delivery. The site integrates advanced analytics and experimentation tools such as Google Analytics 4 and Optimizely, supporting data-driven marketing strategies. The presence of structured data (JSON-LD) enhances SEO and content discoverability. Performance metrics indicate fast load times and excellent mobile optimization. The technical stack supports scalability and extensibility, with a comprehensive plugin and integration ecosystem. However, the invalid SSL certificate and lack of modern TLS support represent technical risks that should be addressed promptly.
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 +11Low26 findingsView report
  2. 67/100 −12Medium23 findingsView report
  3. 79/100Low25 findingsView report
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