• $100 – $1,500 per vulnerability
  • Up to $3,000 maximum reward
  • Partial safe harbor
  • Managed by Bugcrowd

Program stats

128 vulnerabilities rewarded

Validation within 2 days
75% of submissions are accepted or rejected within 2 days

$925 average payout (last 3 months)

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Please note: This program does not allow disclosure. You may not release information about vulnerabilities found in this program to the public.

Mailgun empowers developers by allowing them to easily integrate email into their applications. With our powerful API, users can build apps that send, receive, and track emails in real time using a combination of standard protocols. We work hard to keep Mailgun high performing and secure for our user community. Help us make our products even better and earn rewards by reporting potential vulnerabilities.

Maximum Reward

There is a $3,000 bonus for P1 reports related to Mailgun's SSO functionality. SSO functionality extends throughout the and targets: Implementation Guide

Getting Started

Focus Areas

Mailgun places the utmost value on its customers’ data and trust. The following report outcomes are prioritized by Mailgun Security and will be accepted as P1 or P2 based on impact:

  • Ability to exfiltrate customer data from the platform
  • Unauthorized takeover of a customer account
  • Running code on Mailgun-owned infrastructure


For the initial prioritization/rating of findings, this program will use the Bugcrowd Vulnerability Rating Taxonomy. However, it is important to note that in some cases a vulnerability priority will be modified due to its likelihood or impact. In any instance where an issue is downgraded, a full, detailed explanation will be provided to the researcher - along with the opportunity to appeal, and make a case for a higher priority.

Please note that all leaked API keys found on Github are specifically excluded from the program.

Out Of Scope VRT Categories

Based on the nature of Mailgun's services and architecture, the following VRT Categories are considered Out of Scope:

  • Cross Site Scripting (XSS)
  • Denial of Service
  • Social Engineering

Scope and rewards

Program rules

This program follows Bugcrowd’s standard disclosure terms.

For any testing issues (such as broken credentials, inaccessible application, or Bugcrowd Ninja email problems), please email We will address your issue as soon as possible.

This program does not offer financial or point-based rewards for P5 — Informational findings. Learn more about Bugcrowd’s VRT.