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Security report for slack.com

Slack Technologies, LLC · Technology · United States

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

Security score

80/100

Risk levelLow

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

Slack Technologies, LLC operates Slack.com, a leading enterprise collaboration and productivity platform integrated with AI capabilities. As a Salesforce company, Slack holds a strong market position in the technology sector, offering services such as team messaging, workflow automation, and enterprise search. The website reflects a mature digital presence with excellent content quality, professional design, and clear navigation tailored for business professionals and enterprises. The technical infrastructure leverages modern technologies including AWS hosting, React-based frontend, and CDN delivery for optimal performance and scalability. Security posture is robust with HTTPS enforcement, multiple security headers, and recognized certifications like SOC 2 and ISO 27001. Privacy compliance is well addressed with comprehensive policies and cookie consent mechanisms. Overall, Slack.com demonstrates a high level of business credibility and digital maturity.

Scanned

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

NIS2 and GDPR posture

GDPR outside view
88/ 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. 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. 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 slack.com

This scan found 15 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.

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Recommended

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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
62
Security headers
55
Email security
85
DNS health
90
Network security
100
GDPR outside view
88
Average
80

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

Slack's business model is SaaS-based, targeting enterprises and teams across various industries with a focus on enhancing workplace communication and productivity. The company benefits from its integration within the Salesforce ecosystem, providing competitive advantages through CRM insights and AI-powered agents. Revenue streams primarily come from subscription plans and enterprise offerings. The website's extensive resources, templates, and developer support indicate a strong ecosystem and partnership network. Growth indicators include continuous feature innovation and AI integration. Strategic observations highlight Slack's emphasis on security, compliance, and user engagement to maintain market leadership.

Security posture

Slack.com exhibits a mature security posture with enforced HTTPS, comprehensive security headers, and adherence to industry certifications such as SOC 2 and ISO 27001. The domain registration is transparent and consistent with the company's history, with domain status protections preventing unauthorized changes. Cookie consent and privacy policies align with GDPR requirements. However, the absence of a published security.txt and explicit incident response contacts suggests areas for improvement. No vulnerabilities or exposed sensitive data were detected in the analyzed content. Overall, Slack demonstrates readiness for incident response and data protection, supporting its enterprise clientele.

Recommendations

  1. Enable DNSSEC to enhance DNS security and prevent spoofing.
  2. Publish a security.txt file to facilitate responsible vulnerability disclosure.
  3. Provide explicit incident response contact information on the website.
  4. Regularly audit third-party scripts and libraries for vulnerabilities.
  5. Enhance transparency on data retention policies and user data handling.
Site observations

Automated reading of the public site. Ratings are indicative.

Business

Company
Slack Technologies, LLC
Description
Slack is where work happens. Bring your people, projects, tools, and AI together on the world’s most beloved work operating system.
Key services
Team messaging, Channels, Slack Connect, Workflow automation, Enterprise search, AI-powered agents
Content quality
excellent
Branding
consistent

Technology

Stack
JavaScript, AWS (implied by AWS DNS servers), YouTube iframe API, OneTrust (cookie consent), Optimizely (A/B testing), Cloudfront CDN
Frameworks
React (likely), Optimizely
Platforms
AWS
Performance
fast
Mobile
excellent
Accessibility
good
SEO
good

Security

Observed score
90/100
Good practices seen
  • HTTPS enforced
  • Domain status includes client and server prohibitions for deletion, transfer, update
  • Cookie consent mechanism implemented
  • No DNSSEC (not enabled)
  • Use of security certifications

Analytics and tracking

Services
Optimizely
Tracking level
moderate
Privacy practices
good

Advertising

Tracking pixels
Optimizely, OneTrust
Marketing tools
Optimizely, OneTrust
Transparency
good

Site quality

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

Key observations

  1. Website is fully accessible with no blocking or WAF challenges.
  2. Comprehensive navigation structure with detailed sections on features, solutions, resources, and enterprise offerings.
  3. Strong emphasis on security and compliance with dedicated security and trust pages.
  4. Use of modern web technologies and CDNs for performance and reliability.
  5. Cookie consent and privacy compliance mechanisms are implemented.
  6. No exposed sensitive data or security vulnerabilities detected in the HTML content.
  7. No direct company contact emails or phone numbers found in the HTML; contact primarily via forms and support pages.
Technical notes

Notes

The website is built on a modern technology stack including JavaScript frameworks (likely React), AWS hosting, and CDN distribution via Cloudfront. It employs third-party services such as OneTrust for cookie consent and Optimizely for A/B testing and analytics. The site is mobile-optimized with responsive design and accessibility considerations. Performance is fast due to efficient resource loading and caching strategies. The technical implementation reflects a well-maintained and scalable infrastructure suitable for enterprise-grade applications. Opportunities exist to further modernize DNS security and improve incident response visibility.
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. 77/100Low26 findingsView report
  2. 77/100 +4Low26 findingsView report
  3. 73/100Medium22 findingsView report
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