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Security report for mattermost.com

Mattermost · Technology · United States

Low risk. 2 critical or high findings in SSL/TLS.

Security score

83/100

Risk levelLow

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

Mattermost is a technology company specializing in secure collaboration platforms designed for mission-critical workflows. Their platform integrates people, processes, tools, and AI infrastructure to provide a resilient and adaptable environment for enterprise communication and workflow management. Positioned as a trusted and flexible solution, Mattermost targets medium to large enterprises requiring secure and customizable collaboration tools. The company was founded in 2012 and operates primarily from the United States, with a strong emphasis on security and compliance.

Scanned

NIS2 and GDPR posture

GDPR outside view
100/ 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.

    • 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
    • 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 mattermost.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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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
57
Security headers
80
Email security
75
DNS health
85
Network security
100
GDPR outside view
100
Average
83

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

Breach exposure

Leaked credentials and lookalike domains from OffSeq Breach. The counts are free; the detailed lists are paid add-ons.

Dark web exposure

Add-on

Leaked records that mention mattermost.com, from OffSeq Breach.

Total records
2,173
Employees
0
Customers
2,170
Third parties
3
Weak passwords
9%

313 subdomains affected

See the 10 newest leaked credentials

A one-off add-on to this report that lists the most recent identifier and password pairs OffSeq Breach holds for mattermost.com.

Select it in the checkout above.

Breach keeps ingesting new leaks, so these numbers can grow between scans.

Technical appendix

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

Business context

Business profile

Mattermost holds a solid market position as a secure collaboration platform provider, leveraging certifications such as SOC 2 and ISO 27001 to build trust with enterprise customers. Their business model focuses on enterprise software sales and integration services, targeting organizations with stringent security and workflow requirements. The company maintains active social media profiles and partners with recognized platforms to enhance its market presence. Their website content and technical infrastructure reflect a mature digital strategy with strong SEO and user experience focus.

Security posture

The website demonstrates a mature security posture with HTTPS enforcement, comprehensive security headers, and cookie consent mechanisms compliant with GDPR. The presence of a dedicated security page and incident response contacts indicates readiness for security incidents. No vulnerabilities or exposed sensitive data were detected in the analysis. However, enabling DNSSEC and publishing a security.txt file could further enhance their security transparency and posture. Overall, Mattermost exhibits strong security practices aligned with enterprise expectations.

Recommendations

  1. Enable DNSSEC on the domain to improve DNS security and prevent spoofing.
  2. Publish a security.txt file to facilitate responsible vulnerability disclosure.
  3. Add explicit Data Protection Officer contact information to enhance GDPR compliance transparency.
  4. Regularly review and update third-party scripts and libraries to mitigate potential vulnerabilities.
  5. Continue enhancing privacy compliance by documenting data retention policies and user rights clearly.

Contact details published on the site

Addresses
Legal name
Mattermost
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Mattermost
Description
Accelerate your mission critical workflow by integrating people, processes, tools and AI infrastructure on a resilient and adaptable platform.
Key services
Secure collaboration platform, Workflow integration, AI infrastructure integration
Content quality
excellent
Branding
consistent

Technology

Stack
Google Analytics, Google Tag Manager, OneTrust Cookie Consent, Yoast SEO, WP Rocket, WordPress
Frameworks
Yoast SEO, OneTrust Consent Management
Platforms
WordPress CMS
Performance
fast
Mobile
excellent
Accessibility
good
SEO
excellent

Security

Observed score
90/100
Good practices seen
  • HTTPS enforced
  • Use of security headers
  • Cookie consent mechanism implemented
  • No exposed sensitive data detected
  • Secure forms with consent checkboxes

Analytics and tracking

Services
Google Analytics, Google Tag Manager
Tracking level
moderate
Privacy practices
good

Advertising

Marketing tools
Mutiny personalization, OneTrust cookie consent
Transparency
good

Site quality

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

Key observations

  1. Website uses HTTPS with strong security headers
  2. Comprehensive privacy and cookie policies with consent mechanisms
  3. Clear business and contact information including physical address in Palo Alto, CA
  4. Use of modern web technologies and SEO best practices
  5. Presence of social media links to official company profiles
  6. No signs of suspicious or malicious activity
  7. No adult or questionable content detected
Technical notes

Notes

Mattermost's website is built on WordPress CMS with modern SEO and performance optimization plugins such as Yoast SEO and WP Rocket. The site uses Google Analytics and Google Tag Manager for analytics and tracking, alongside OneTrust for cookie consent management. Hosting is managed via Amazon Registrar with AWS DNS servers, ensuring reliable infrastructure. The site is mobile-optimized, fast-loading, and accessible, with a consistent branding and professional design. The technical stack and infrastructure support the company's enterprise-grade service offerings effectively.
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

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