Hoplr is the social network for inclusion and citizen engagement. As a social network we consider the safety and continuity of our online services as one of our top priorities. Our team is continually working to optimize our systems and processes, yet despite all the efforts we make to secure our systems, vulnerabilities may still be present. We are happy with your help to further improve our systems and to protect our users and customers even better.


Responsible disclosure

Rules of engagement
Not applicable
max. 5 requests/sec
Not applicable

Our promise to you

  • We are happy to respond to any questions, please use the button in the right top corner for this.
  • We respect the safe harbour clause that you can find below

Your promise to us

  • Always create a Hoplr account with your address
  • Provide detailed but to-the point reproduction steps
  • Include a clear attack scenario. How will this affect us exactly?
  • Remember: quality over quantity!
  • Please do not discuss or post vulnerabilities without our consent (including PoC's on YouTube and Vimeo)
  • Please do not use automatic scanners -be creative and do it yourself! We cannot accept any submissions found by using automatic scanners. Scanners also won't improve your skills, and can cause a high server load (we'd like to put our time in thanking researchers rather than blocking their IP's 😉)


No Bounty
No Bounty
No Bounty
In scope

We are interested to learn about any potential vulnerabiliity that could impact the security and privacy of our users or customers.
Examples of issues we would like to know more about:

  • Theft of sensitive data
  • Unauthorized modification or deletion of sensitive data
  • Access to other neighbourhoods than the one in which you have a valid membership for. The membership only gives you access to one neighbourhood.
  • Engage with neighbourhoods on behalf of cities or other customers
  • DOS on the level of neighbourhood. Posting content that prevents the neighbourhood (Messages) feed from loading. No request flooding and nothing that causes the website to go down


  • Social Network ( Citizens use Hoplr to share goods and services, organize neighbourhood activities, report problems, find lost pets, meet new neighbours, discuss safety, participate in local policy making and so much more.
  • Service Dashboard ( Hoplr offers the public sector -local authorities, local utility services, project developers and any local organisation that brings non-commercial value to citizens -a service dashboard to engage with local communities.


Access codes to register an accepted user account in test neighbourhoods can be requested when logged in by using the request credentials button in the upper right corner of our program's page.

More info can be found on:

Out of scope


  • Pre-auth account takeover / oauth squatting
  • Self-XSS that cannot be used to exploit other users 
  • Verbose messages/files/directory listings without disclosing any sensitive information
  • CORS misconfiguration on non-sensitive endpoints
  • Missing cookie flags
  • Missing security headers
  • Cross-site Request Forgery with no or low impact
  • Presence of autocomplete attribute on web forms
  • Reverse tabnabbing
  • Bypassing rate-limits or the non-existence of rate-limits.
  • Best practices violations (password complexity, expiration, re-use, etc.)
  • Clickjacking on pages with no sensitive actions
  • CSV Injection
  • Host header injection without proven business impact
  • Blind SSRF without proven business impact (DNS pingback only is not sufficient)
  • Disclosed and/or misconfigured Google API key (including maps)
  • Sessions not being invalidated (logout, enabling 2FA, ..)
  • Hyperlink injection/takeovers
  • Mixed content type issues
  • Cross-domain referer leakage
  • Anything related to email spoofing, SPF, DMARC or DKIM
  • Content injection
  • Username / email enumeration
  • E-mail bombing
  • HTTP Request smuggling without any proven impact
  • Homograph attacks
  • XMLRPC enabled
  • Banner grabbing / Version disclosure
  • Open ports without an accompanying proof-of-concept demonstrating vulnerability
  • Weak SSL configurations and SSL/TLS scan reports
  • Not stripping metadata of images
  • Disclosing credentials without proven impact
  • Disclosing API keys without proven impact
  • Same-site scripting
  • Subdomain takeover without taken over the subdomain
  • Arbitrary file upload without proof of the existence of the uploaded file


  • In case that a reported vulnerability was already known to the company from their own tests, it will be flagged as a duplicate.
  • Theoretical security issues with no realistic exploit scenario(s) or attack surfaces, or issues that would require complex end user interactions to be exploited, may be excluded or be lowered in severity
  • Spam, social engineering and physical intrusion
  • DoS/DDoS attacks or brute force attacks.
  • Vulnerabilities that are limited to non-current browsers (older than 3 versions) will not be accepted
  • Attacks requiring physical access to a victim’s computer/device, man in the middle or compromised user accounts
  • Recently disclosed zero-day vulnerabilities in commercial products where no patch or a recent patch (< 2 weeks) is available. We need time to patch our systems just like everyone else - please give us 2 weeks before reporting these types of issues.
  • Reports that state that software is out of date/vulnerable without a proof-of-concept
  • Access to a neighbourhood with someone else's address and using the regular "Find my neighbourhood" flow on the website or in the app


  • Shared links leaked through the system clipboard
  • Any URIs leaked because a malicious app has permission to view URIs opened
  • The absence of certificate pinning
  • Sensitive data in URLs/request bodies when protected by TLS
  • Lack of obfuscation
  • Path disclosure in the binary
  • Lack of jailbreak & root detection
  • Crashes due to malformed URL Schemes
  • Lack of binary protection (anti-debugging) controls, mobile SSL pinning
  • Snapshot/Pasteboard leakage
  • Runtime hacking exploits (exploits only possible in a jailbroken environment)
  • API key leakage used for insensitive activities/actions
  • Attacks requiring physical access to the victim's device
  • Attacks requiring installing malicious applications onto the victim's device
Severity assessment

This program follows Intigriti's contextual CVSS standard.


Where can we get credentials for the app?

You can self-register, but please use your email address and join either Herstappe Zuid or Herstappe Noord! You can find the codes to join these by claiming credentials with the button on the top right of this page. You will need a valid address in either district, feel free to search for that. Here is an example of how to join Herstappe Zuid successfully:

  1. Go to
  2. Enter a valid address for Herstappe Zuid, an example would be Villers-l’Evêquestraat 17
  3. Enter the code in the credentials PDF for Herstappe Zuid
All aboard!
Please log in or sign up on the platform

For obvious reasons we can only allow submissions or applications for our program with a valid intigriti account.

It will only take 2 minutes to create a new one or even less to log in with an existing account, so don't hesitate and let's get started. We would be thrilled to have you as part of our community.

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