System security is a top priority at Leaseweb. Regardless of the amount of effort we put into the security of our systems, there can still be vulnerabilities present. No technology is perfect, and Leaseweb believes that working with skilled security researchers across the globe is crucial in identifying any weaknesses. We encourage you to notify us iIf you believe you have identified a security issue in our product or service so we can work together to promptly resolve the issue.

Guidelines for Responsible Disclosure

  • Notify us as soon as possible upon discovery of a potential security issue. We will make every effort to quickly resolve the issue.
  • Provide us a reasonable amount of time to resolve the issue before any disclosure to the public or a third -party.
  • Only use official communication channels. Do not use personal emails, social media accounts, or other private connections to contact a member of the security team in regard to vulnerabilities or any program related issues, unless you have been instructed to do so by the program.
  • No unauthorized impersonation: any unauthorized attempts to socially engineer another party through impersonation of a Leaseweb employee, another hacker, or a security team will not be tolerated.
  • If you comply with all conditions set in these guidelines we will not take any legal action against you regarding this report.
  • Your report will be confidential and we will not share your personal information with third parties without prior consent, unless it is necessary to comply with a legal obligation.
  • Free services for security researchers: we may refund the costs of Leaseweb services if vulnerabilities within our systems are found. The decision to refund and the subsequent amount refunded is at the discretion of Leaseweb.
  • Difference between Leaseweb services and customer services: vulnerabilities may be found in customer’s services that are leased from Leaseweb but not managed by us. If these vulnerabilities are discovered, we will be unable to resolve the issue or offer any rewards. If this happens, we will put you in contact with our customer, if it is feasible.


To show our appreciation of responsible security researchers, Leaseweb offers bounties for reports of qualifying security vulnerabilities. Bounties will be awarded in the form of financial compensation(s) or Leaseweb merchandise. The amount that is rewarded per bounty is at the discretion of Leaseweb and will be based on the internal severity rating of the disclosed vulnerability. The bounty will be communicated after validation of the security vulnerability by our internal teams.


To qualify for a reward, you must:

  • Be the first reporter of the vulnerability
  • Follow the guidelines as described on this page
  • Not publicly disclose the vulnerability prior to our resolution
  • Provide a working proof of concept that exploits the security issue. The PoC should include at least:
  1. Details on what the vulnerability is 
  2. The steps that we should take to reproduce the vulnerability 
  3. What kind of impact the attack would have if the vulnerability is exploited 
  • Solely use your created accounts and not access data of other users
  • Not be an inhabitant of any country listed on the Specially Designated Nationals and Blocked Persons (SDN) list
  • Not be an inhabitant of any country listed on the Consolidated List of persons, groups and entities subject to EU Financial Sanctions list


While researching, we would like to ask you to refrain from:

  • Social engineering (including phishing) of Leaseweb staff or contractors
  • Any physical attempts against Leaseweb property or data centers
  • Physical attack on the infrastructure
  • Denial of service
  • Login/Logout CSRF
  • Self-XSS (we require evidence on how the XSS can be used to attack another Leaseweb user)
  • Missing of rate limits
  • Report from automated tools and scans
  • Bugs in 3rd party software
  • X-Frame-Options related
  • Missing cookie flags on non-sensitive cookies
  • Missing security headers which do not lead directly to a vulnerability (unless you deliver a PoC)
  • DKIM/SPF/DMARC issues (we are aware they are missing and working on resolution)
  • Version exposure (unless you deliver a PoC of working exploit)
  • Directory listing with already public readable content
  • Content spoofing on error pages or text injection

How to Report

Please send your initial findings to If needed, you can use our PGP-key to encrypt your message. This key can be found here.

Thank you for helping to keep Leaseweb and our users safe!