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Security report for cal.com

Cal.com · Technology · N/a

Low risk. 5 critical or high findings in Security headers, GDPR outside view and 1 other check.

Security score

76/100

Risk levelLow

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

Cal.com is a technology company providing an open scheduling infrastructure platform designed for individuals, businesses, and developers. Their core offering is a fully customizable scheduling software that facilitates calls and meetings, positioning them as a SaaS provider in the scheduling software market. The website demonstrates a modern technical infrastructure using the Framer framework, Cloudflare DNS hosting, and integrates advertising and analytics tools such as Twitter Ads and Google Analytics. The site is well-designed with good mobile optimization and SEO practices, though accessibility is basic. Security posture is solid with HTTPS enabled and domain registration protections, but lacks DNSSEC and security headers. Privacy compliance is weak due to missing privacy and cookie policies and absence of consent mechanisms. No contact or incident response information is provided, limiting transparency. Overall, the website is professional and trustworthy but would benefit from enhanced privacy and security disclosures.

Scanned

NIS2 and GDPR posture

GDPR outside view
65/ 100 · Medium
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 X-Frame-Options header

      Prevents clickjacking attacks

      What to do: Add "X-Frame-Options: DENY" or "X-Frame-Options: SAMEORIGIN"

    • 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 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

  3. 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.

    • High

      Weak SSL Key Length

      SSL certificate uses 256-bit key, which is considered weak

      What to do: Use at least 2048-bit RSA or 256-bit ECC key

      • CWE-326
      • OWASP A04:2025
      • Mozilla TLS: Mozilla Server Side TLS 6.0 intermediate: rsa_key_size 2048

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

Keep watching cal.com

This scan found 16 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.

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

Email alerts on material changes and an exportable JSON history of every change.

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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
75
Security headers
40
Email security
87
DNS health
90
Network security
100
GDPR outside view
65
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

Cal.com operates in the technology sector with a focus on scheduling software as a service. The company targets a broad audience including individuals, businesses, and developers, offering customizable scheduling solutions. The domain age of over 25 years supports a mature business presence. The business model is subscription or platform-based SaaS. The website content is consistent and professional, though lacks explicit trust signals such as certifications or testimonials. Advertising partnerships include Twitter Ads and Google marketing tools. The company appears to maintain a moderate digital footprint with no evident privacy protection on domain registration, indicating transparency. Growth potential is supported by the open infrastructure approach appealing to developers and businesses.

Security posture

The website employs HTTPS and Cloudflare DNS, providing a secure transport layer and reliable DNS hosting. However, DNSSEC is not enabled, which is a recommended security enhancement. No security headers such as Content-Security-Policy or X-Frame-Options were detected, which could improve protection against common web attacks. There is no published security policy, incident response plan, or vulnerability disclosure program visible on the site, which limits the ability to respond to security incidents effectively. No exposed sensitive data or vulnerable libraries were identified in the provided content. Overall, the security posture is moderate but could be improved by implementing additional security headers, enabling DNSSEC, and publishing security and incident response information.

Recommendations

  1. Enable DNSSEC on the domain to enhance DNS security and prevent spoofing.
  2. Implement and publish a comprehensive privacy policy and cookie consent mechanism to improve GDPR compliance and user trust.
  3. Add security headers such as Content-Security-Policy, X-Frame-Options, and X-Content-Type-Options to harden the website against common attacks.
  4. Provide clear contact information including security incident response contacts and consider publishing a security policy or security.txt file.
  5. Conduct a security audit to identify and remediate any potential vulnerabilities and improve overall security posture.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Cal.com
Description
A fully customizable scheduling software for individuals, businesses taking calls and developers building scheduling platforms where users meet users.
Key services
customizable scheduling software, platform for scheduling calls and meetings
Content quality
good
Branding
consistent

Technology

Stack
JavaScript, Google Tag Manager, Twitter Ads SDK, Cloudflare DNS
Frameworks
Framer
Performance
moderate
Mobile
good
Accessibility
basic
SEO
good

Security

Observed score
75/100
Good practices seen
  • HTTPS enabled
  • Domain status includes clientDeleteProhibited, clientRenewProhibited, clientTransferProhibited, clientUpdateProhibited

Analytics and tracking

Services
Google Analytics
Tracking level
moderate
Privacy practices
poor

Advertising

Ad networks
Twitter Ads
Tracking pixels
Google Analytics (via Google Tag Manager), Twitter tracking
Transparency
basic

Site quality

Design
good
User experience
good
Content relevance
good
Navigation
good
Professionalism
good
Trustworthiness
moderate

Key observations

  1. Website uses modern front-end framework (Framer)
  2. No explicit privacy or cookie policies found in the HTML content
  3. No contact emails or phone numbers found in the provided content
  4. No security.txt or vulnerability disclosure information found
  5. Website uses HTTPS and Cloudflare DNS but DNSSEC is not enabled
  6. Advertising and tracking scripts from Twitter and Google are present
  7. No signs of WAF blocking or security challenges
  8. Content is professional and relevant to scheduling software
Technical notes

Notes

The website is built using the Framer framework, indicating a modern front-end development approach focused on design and user experience. Hosting is managed via Cloudflare DNS, providing reliable and performant DNS resolution. The site integrates Google Tag Manager and Twitter Ads SDK for analytics and marketing purposes. Fonts are loaded from Google Fonts, ensuring consistent typography. The website is mobile optimized and SEO friendly with appropriate meta tags and Open Graph data. Performance is moderate, with asynchronous loading of scripts to improve page load times. Accessibility is basic and could be enhanced. No CMS other than Framer is detected. Overall, the technical infrastructure is solid but could benefit from additional accessibility and security enhancements.
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. 76/100 +8Low24 findingsView report
  2. 68/100Medium26 findingsView report
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