Skip to main content

Security report for mastodon.nl

Stichting Activityclub · Technology · Netherlands

Medium risk. 4 critical or high findings in GDPR outside view and SSL/TLS.

Security score

74/100

Risk levelMedium

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

Mastodon.nl is an independent Mastodon server operated by Stichting Activityclub, serving the Dutch Mastodon and fediverse community. It provides a social networking platform focused on community engagement without ads or algorithms, emphasizing privacy and open source principles. The website is well designed, mobile optimized, and offers features such as trending posts and profile directories. Technically, it runs Mastodon version 4.4.7 with modern web technologies including Ruby on Rails and React, and employs secure HTTPS connections with DNSSEC enabled for domain security. Security posture is strong with no evident vulnerabilities or exposed sensitive data, though some security headers could be improved. Privacy compliance is basic, with a privacy policy present but lacking cookie consent mechanisms and terms of service. Overall, the site is trustworthy and professional, catering to a niche community audience.

Scanned

NIS2 and GDPR posture

GDPR outside view
33/ 100 · High
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

4 findings rated critical or high. Fix these first.

  1. GDPR outside view

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

    • Critical

      EU business without adequate privacy measures

      EU businesses are subject to strict GDPR requirements

      What to do: Implement comprehensive GDPR compliance including privacy policy, cookie consent, and data protection measures

    • 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

  2. 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 Protocols Supported

      Server supports weak protocols: TLSv1.1

      What to do: Disable TLS 1.0, TLS 1.1, and all SSL versions

      • CWE-327
      • OWASP A04:2025
      • ASVS V12.1.1

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

Keep watching mastodon.nl

This scan found 19 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.

Billed monthly to your card. Cancel anytime. The full timeline opens with your unlock code.

Full report

€39.90one-time

  • The complete analysis as a PDF you can cite
  • Email delivery with an unlock code
  • Lifetime access to this report

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
72
Security headers
80
Email security
85
DNS health
75
Network security
100
GDPR outside view
33
Average
74

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

The business operates as a non-profit entity focused on providing a Mastodon instance for the Dutch-speaking community. It leverages open source software and community contributions to maintain its platform. The target audience includes Dutch Mastodon users and broader fediverse participants. The organization benefits from a stable domain registration since 2013 and maintains transparency about its administration. The business model is community-driven without commercial advertising or monetization. Partnerships or subsidiaries are not evident. Growth indicators include active user statistics and ongoing platform updates. Strategic observations suggest opportunities to enhance privacy compliance and formalize security policies to strengthen trust further.

Security posture

The website demonstrates a mature security posture with HTTPS enforced, DNSSEC enabled, and use of script integrity attributes. No critical vulnerabilities or exposed sensitive data were detected in the HTML content. However, the absence of certain security headers like Content-Security-Policy and X-Frame-Options represents an area for improvement. There is no published security policy or incident response information, which could enhance transparency and readiness. Privacy compliance gaps exist, notably the lack of cookie consent mechanisms and terms of service. Overall, the security maturity is good but could benefit from formalized policies and additional header protections.

Recommendations

  1. Implement a cookie consent banner to comply with privacy regulations and improve user transparency.
  2. Publish a comprehensive terms of service page to clarify user rights and responsibilities.
  3. Add security headers such as Content-Security-Policy, X-Frame-Options, and Strict-Transport-Security to enhance protection.
  4. Establish and publish a security policy and incident response plan to improve trust and readiness.
  5. Consider adding explicit contact information for security and general inquiries to improve business credibility.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Stichting Activityclub
Description
Mastodon voor de Nederlandse community - door de Nederlandse community - in stand gehouden door Stichting Activityclub
Key services
Mastodon social networking server, Community hosting, Profile directory, Trending posts
Content quality
good
Branding
consistent

Technology

Stack
Mastodon 4.4.7, Ruby on Rails, React, SVG icons, WebSockets (wss)
Frameworks
Ruby on Rails, React
Platforms
Fediverse, Mastodon
Performance
fast
Mobile
good
Accessibility
good
SEO
good

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced
  • No exposed sensitive data in HTML
  • Use of integrity attributes on scripts and stylesheets

Analytics and tracking

Tracking level
minimal
Privacy practices
basic

Advertising

Transparency
poor

Site quality

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

Key observations

  1. Website is a Mastodon instance for the Dutch community
  2. Content is publicly accessible and well structured
  3. No privacy or cookie consent banners present
  4. No terms of service page detected
  5. No explicit contact emails or phone numbers found
  6. Uses modern web technologies and good security practices
  7. No advertising or tracking detected
Technical notes

Notes

The website uses a modern technology stack centered on Mastodon 4.4.7, Ruby on Rails backend, and React frontend components. It leverages WebSockets for real-time streaming and includes well-structured meta tags and Open Graph data for SEO and social sharing. Performance is optimized with module preloading and integrity checks on scripts and stylesheets. Mobile optimization and accessibility are well addressed. Hosting details are not explicitly disclosed but domain registration is stable and DNSSEC is enabled, indicating good domain security practices. There is no evidence of technical debt or legacy technology usage. Opportunities exist to enhance security headers and privacy compliance features.
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. 77/100Low25 findingsView report
Reviews of this site

Share your experience with mastodon.nl. Every review is verified by email and published after moderation.

Overall rating
Select a rating
4000 characters remaining

We’ll email you to confirm your review and keep your details private.

Community rating

No published reviews yet. Be the first to review mastodon.nl.

Feedback on this report

Rate this report, add an optional comment, and tell us if you want a security specialist to follow up.

Overall report quality
Select a rating
2000 characters remaining

We only use your feedback to improve Guard reports. Contact details are never shared.