Vulnerability Disclosure Policy

Payhawk greatly appreciates investigative work into security vulnerabilities which are carried out by well-intentioned, ethical security researchers. We are committed to thoroughly investigating and resolving security issues in our platform and services in collaboration with the security community. This document aims to define a method by which Payhawk can work with the security research community to improve our online security.


Vulnerabilities in Payhawk products and services are only within the scope of the Bug Bounty Scheme when they meet the following conditions:

  • They have not been previously reported or have not already been discovered by our own internal procedures;
  • It can be demonstrated that there would be a real impact to Payhawk, its users or its customers should the vulnerability reported be exploited by a malicious actor. The existence of a vulnerability does not necessarily demonstrate that such a potential impact exists: theoretical impacts will not be considered within the scope of the scheme;
  • It exists within a domain that has a security.txt file in its root. Subdomains are considered in the scope provided their parent domain is in scope. (i.e. the existence of https://<>/security.txt means that and are also in scope.)

The following security issues are currently not in scope (please don’t report them):

  • Volumetric/Denial of Service vulnerabilities (i.e. simply overwhelming our service with a high volume of requests);
  • TLS configuration weaknesses (e.g. “weak” cipher suite support, TLS1.0 support, sweet32, etc.);
  • Reports indicating that our services do not fully align with “best practice” (e.g. missing security headers or suboptimal email-related configurations such as SPF, DMARC, etc.);
  • Issues surrounding the verification of email addresses used to create user accounts;
  • Clickjacking vulnerabilities;
  • Self XSS / DOM Based XSS (i.e. where a user would need to be tricked into pasting code into their web browser);
  • CSRF where the resulting impact is minimal;
  • CRLF attacks where the resulting impact is minimal;
  • Host header injection where the resulting impact is minimal;
  • Network data enumeration techniques (e.g. banner grabbing, existence of publicly available server diagnostic pages);
  • Reports of improper session management/session fixation vulnerabilities.
Bug Bounty

Unfortunately, due to the Payhawk funding structure, it is not currently possible for us to offer a paid bug bounty program. We would, however, like to offer a token of our appreciation to security researchers who take the time and effort to investigate and report security vulnerabilities to us according to this policy. Reporters of qualifying vulnerabilities will be offered a unique Payhawk reward.

Reporting a vulnerability

If you have discovered an issue that you believe is an in-scope security vulnerability (please see section 2 above for more detail on scope), please email ensuring the communication is encrypted with our public key hosted at: with serial: 29E9A9EE82D1DC0A

  • The website or page in which the vulnerability exists.
  • A brief description of the class (e.g. “XSS vulnerability”) of the vulnerability.
  • Steps to reproduce the vulnerability, including screenshots, recordings, or other information that would be necessary.

In accordance with industry convention, we ask that reporters provide benign (i.e. non-destructive) proof of exploitation wherever possible. This helps to ensure that the report can be triaged quickly and accurately whilst also reducing the likelihood of duplicate reports and/or malicious exploitation for some vulnerability classes (e.g. sub-domain takeovers). Please ensure that you do not send your proof of exploit in the initial, plaintext email if the vulnerability is still exploitable. Please also ensure that all proof of exploits is in accordance with our guidance (below), if you are in any doubt, please email for advice.

Please read this document fully prior to reporting any vulnerabilities to ensure that you understand the policy and can act in compliance with it.

What to expect

In response to your initial email to, you will receive an acknowledgment reply email from the Payhawk Security Team, this is usually within 24 hours of your report being received. The acknowledgment email will include a ticket reference number which you can quote in any further communications with our Security Team.

Following the initial contact, our Security Team will work to triage the reported vulnerability and will respond to you as soon as possible to confirm whether further information is required and/or whether the vulnerability qualifies as per the above scope, or is a duplicate report. From this point, necessary remediation work will be assigned to the appropriate Payhawk teams and/or supplier(s). Priority for bug fixes and/or mitigations will be assigned based on the severity of impact and complexity of exploitation. Vulnerability reports may take some time to triage and/or remediate, you’re welcome to enquire on the status of the process but please limit this to no more than once every 14 days, this helps our Security team focus on the reports as much as possible.

Our Security Team will notify you when the reported vulnerability is resolved (or remediation work is scheduled) and will ask you to confirm that the solution covers the vulnerability adequately. We will offer you the opportunity to feedback to us on the process and relationship as well as the vulnerability resolution. This information will be used in strict confidence in order to help us improve the way in which we handle reports and/or develop services and resolve vulnerabilities. We will also offer to include reporters of qualifying vulnerabilities on our acknowledgments page and we’ll ask for the details you wish to be included.


Security researchers must not:

  • Access unnecessary amounts of data. For example, 2 or 3 records are enough to demonstrate most vulnerabilities (such as an enumeration or direct object reference vulnerability);
  • Violate the privacy of Payhawk users, staff, contractors, systems, etc. For example by sharing, redistributing, and/or not properly securing data retrieved from our systems or services;
  • Communicate any vulnerabilities or associated details via methods not described in this policy or with anyone other than your dedicated Payhawk security contact;
  • Modify data in our systems/services which is not your own;
  • Disrupt our service(s) and/or systems; or
  • Disclose any vulnerabilities in Payhawk systems/services to 3rd parties/the public prior to the Payhawk confirming that those vulnerabilities have been mitigated or rectified. This does not prevent notification of a vulnerability to 3rd parties to whom the vulnerability is directly relevant, for example where the vulnerability being reported is in a software library or framework – but details of the specific vulnerability of the Payhawk must not be referenced in such reports. If you are unsure about the status of a 3rd party to whom you wish to send a notification, please email for clarification.

We request that any and all data retrieved during research be securely deleted as soon as it is no longer required and at most, 1 month after the vulnerability is resolved, whichever occurs soonest.
If you are unsure at any stage whether the actions you are thinking of taking are acceptable, please contact our security team for guidance (please do not include any sensitive information in the initial communications):


This policy is designed to be compatible with common good practices among well-intentioned security researchers. It does not give you permission to act in any manner that is inconsistent with the law or cause Payhawk to be in breach of any of its legal obligations, including but not limited to:

  • The Computer Misuse Act (1990)
  • The General Data Protection Regulation 2016/679 (GDPR) and the Data Protection Act 2018
  • The Copyright, Designs, and Patents Act (1988)
    Payhawk will not seek prosecution of any security researcher who reports, in good faith and in accordance with this policy, any security vulnerability on an in-scope Payhawk service.

If you wish to provide feedback or suggestions on this policy, please contact our security team: This policy will evolve over time and your input will be valued to ensure that it is clear, complete, and remains relevant.