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Security report for mastodon.nl

Stichting Activityclub · Technology · Netherlands

Low risk. 3 critical or high findings in GDPR outside view.

Security score

77/100

Risk levelLow

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. The website demonstrates a mature presence with a domain registered since 2013 and active user engagement. Technically, it uses modern web technologies including React and WebSockets for real-time streaming, with good mobile optimization and accessibility basics. Security posture is strong with HTTPS and DNSSEC enabled, though explicit security policies and cookie consent mechanisms are missing. Overall, the platform is trustworthy and professionally maintained but could improve privacy compliance and transparency with additional policy pages.

Scanned

This is an earlier scan of mastodon.nl. View the latest report

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

3 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

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

Keep watching mastodon.nl

This scan found 17 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

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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
95
Security headers
75
Email security
85
DNS health
75
Network security
100
GDPR outside view
33
Average
77

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

Mastodon.nl targets Dutch-speaking users interested in decentralized social networking. Its non-profit model focuses on community hosting rather than commercial revenue. The platform leverages open-source Mastodon software, positioning itself as a key player in the Dutch fediverse ecosystem. The presence of active users and curated trending content indicates healthy community engagement. The lack of advertising and tracking tools aligns with privacy-conscious user expectations. Strategic partnerships or subsidiaries are not evident, emphasizing its independent community-driven nature.

Security posture

The website enforces HTTPS and DNSSEC, indicating strong transport and DNS security. No exposed sensitive data or vulnerable libraries were detected in the HTML content. However, the absence of a published security policy, incident response contacts, or vulnerability disclosure mechanisms limits transparency and preparedness perception. No cookie consent or GDPR compliance indicators were found, which could pose compliance risks. Overall, the security posture is solid technically but lacks formal documentation and user-facing security assurances.

Recommendations

  1. Implement a cookie consent banner to comply with privacy regulations.
  2. Publish terms of service and security policy pages to enhance transparency.
  3. Add a vulnerability disclosure policy or security.txt file to facilitate responsible reporting.
  4. Include incident response contact information such as security@ or abuse@ email addresses.
  5. Enhance accessibility features to improve inclusivity and SEO.
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 exploration
Content quality
good
Branding
consistent

Technology

Stack
React (implied by JSX and React scripts), JavaScript ES Modules, WebSockets (streaming API)
Frameworks
Mastodon (Ruby on Rails based)
Platforms
Fediverse
Performance
moderate
Mobile
good
Accessibility
basic
SEO
basic

Security

Observed score
85/100
Good practices seen
  • HTTPS enforced
  • DNSSEC enabled
  • No exposed sensitive data in HTML
  • No visible vulnerable libraries

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 focused on the Dutch community.
  2. Content is publicly accessible with no blocking or WAF challenges.
  3. No explicit privacy or cookie consent banners found despite privacy policy presence.
  4. No terms of service or security policy pages detected.
  5. No direct company contact emails or phone numbers found on the page.
  6. Uses modern web technologies and serves dynamic social content.
  7. No advertising or tracking scripts detected.
  8. Content is safe and suitable for general audiences.
Technical notes

Notes

The website uses a modern tech stack based on the Mastodon open-source platform, likely Ruby on Rails backend with React frontend components. It employs ES modules and WebSocket streaming for real-time updates. Performance is moderate with good mobile responsiveness and basic accessibility. SEO is supported by meta tags and Open Graph data but could be improved with structured data like JSON-LD. No CMS detected beyond the Mastodon platform. Hosting provider details are not explicit. The site shows no signs of technical debt or deprecated libraries in the provided content.
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. 74/100Medium27 findingsView report
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