Bug bounty

Public

ExpressVPN - Bug Bounty Program

Reward

Bounty

Hall of fame

$50

Low

$200

Medium

$600

High

$1,250

Critical

$2,500

Program

Avg reward

Max reward

Scopes

Supported languages

English

Hacktivity

Reports

1st response

< 1 day

Reports last 24h

Reports last week

Reports this month

Program description

Program activity

ExpressVPN

ExpressVPN operates thousands of VPN servers and makes cross-platform VPN applications for all major desktop and mobile operating systems, as well as routers and browser extensions.

Security is core to our values, and we value the input of hackers acting in good faith to help us maintain a high standard for the security and privacy of our users. This includes encouraging responsible vulnerability research and disclosure. We've offered an in-house bug bounty program for years and paid out thousands of dollars to security researchers in that time. We value excellent engineering and are always looking for ways to improve the security of our products and services.

Scope Description

ExpressVPN Core Functionalities

These are production services that are actively used by ExpressVPN customers and partners.

Included assets:

*.expressvpn.com — Wildcard includes all subdomains and their children.
expressvpn.jobs — recruitment-related integrations
gh-mail.expressvpn.com — Greenhouse ATS integration

ExpressVPN APIs

These are key backend systems used for authentication, service provisioning, and configuration management.

JWKS key location: https://api.jwks.kape.com/.well-known/jwks.json
Staging API: https://xv-cp.apis-staging.xvtest.net
General API Usage: https://api.expressvpn.com
Base API for other Open API spec endpoints: https://cp.expressapisv2.net

Dedicated IP (DIP) API calls go to the following endpoints:

https://api.enc.kape.com
https://api.dbs.kape.com
https://api.dts.kape.com
https://api.blts.kape.com
https://api.pcrs.kape.com
https://api.jwks.kape.com

Reference: You are encouraged to review our OpenAPI spec: expressvpn-apis-openapi.yaml to understand expected behaviors and endpoints.

Browser Extensions

These extensions allow users to control the VPN from their browsers and integrate password management functionality.

Included assets:

Mobile Applications

These native apps provide core VPN connectivity and account features on mobile devices.

Included assets:

Desktop Applications

These VPN clients are designed for use on major desktop operating systems.

Included assets:

Lightway VPN Protocol

ExpressVPN’s in-house VPN protocol focused on speed, security, and reliability. It is open source and available in multiple implementations.

Included assets:

ExpressVPN VPN Servers

ExpressVPN operates a global fleet of VPN servers that users connect to from various devices.

Important notes:

Full list of servers is not publicly available.
A subset is visible through ExpressVPN applications — only these are in-scope.
Brute-forcing, scanning the entire IP space, or disrupting VPN infrastructure is strictly prohibited.

We welcome responsible testing of endpoints exposed via the official apps that reflect real-world usage.

For any submissions related to our VPN servers, please include a screenshot of the VPN application clearly showing the assigned IP address and location used during testing.

Failure to provide this evidence may result in the report being closed or marked as incomplete.

ExpressVPN Aircove & Router Firmware

Aircove is ExpressVPN’s custom VPN router with always-on protection and built-in VPN functionality.

Engineering & Testing Environments

*.xvtest.net

This is the domain for ExpressVPN's and Kape's engineering tools, CI/CD environments, and staging services.

Important notes:

Wildcard includes all subdomains and their children.

Internal & Operational Infrastructure

*.xvservice.net and Subdomains

These domains are used for IT infrastructure, identity services, and deployment workflows.

Key subdomains:

1pw-scim.prd.iat.it.xvservice.net: SCIM for 1Password
gatekeeper.prd.iat.it.xvservice.net: Legacy IAA service
prd.iat.it.xvservice.net, vector.prd.iat.it.xvservice.net: Production identity management
it.xvservice.net: VMware and IT systems

Internal SaaS & IT Domains

*.polymoon.it, corp.polymoon.it: GlobalProtect, SaaS tools
networkguard.com: Redirects, web integrations

Program Rules

Testing Policy & Responsible Disclosure

Please adhere to the following rules while performing research on this program:

Denial of service (DoS) attacks on ExpressVPN applications, servers, networks or infrastructure are strictly forbidden.
Avoid tests that could cause degradation or interruption of our services.
Do not use automated scanners or tools that generate large amount of network traffic.
Do not leak, copy, manipulate, or destroy any user data or files in any of our applications/servers.
No vulnerability disclosure, full, partial or otherwise, is allowed.
Make sure to apply hunting requirements policy (User-Agent, VPN, etc.)

Reports of Credentials Exposure

In the context of this program, we do not intend to encourage, accept or reward reports of credential exposures that are not applicable to our program’s scope and identified outside of our program’s scope, such as:

Exposed credentials in/from an out-of-scope asset/source
Sensitive information exposed in/from an out-of-scope asset/source

To avoid encouraging dark and grey economies (e.g. credential trading, social engineering), we will not accept any report based on information not originating from a failure on our part or that of our service providers.

This includes (but is not limited to):

Stolen credentials gathered from unidentified sources
Credentials not applicable and not found in the in-scope assets
Exposed secrets unrelated to program scope
PII exposed on out-of-scope assets

Summary Table

	Source of credential exposure is in-scope	Belongs to ExpressVPN, out-of-scope	Not ExpressVPN-owned, out-of-scope
Impact is in-scope	✅ Eligible	✅ Eligible	❌ Not Eligible
Impact is out-of-scope	✅ Eligible	❌ Not Eligible	❌ Not Eligible

Important Precautions and Limitations

As a complement to the Program’s rules and testing policy:

DO NOT alter compromised accounts by creating, deleting or modifying any data.
DO NOT use compromised accounts to search for post-auth vulnerabilities (they won’t be eligible anyway).
DO NOT include Personally Identifiable Information (PII) in your report. REDACT/OBFUSCATE all PII in screenshots or payloads.
In case of exposed credentials or secrets, limit yourself to verifying the credentials' validity.
In case of sensitive information leaks, DO NOT extract/copy all data. Only describe and list what's visible.

Reward Eligibility

We are happy to thank everyone who submits valid reports which help us improve the security of ExpressVPN. However, only those that meet the following eligibility requirements may receive a monetary reward:

You must be the first reporter of a vulnerability.
The vulnerability must be a qualifying vulnerability.
The report must contain:
- Clear textual description of the vulnerability
- Security impact on users and systems
- Remediation suggestions
- Proof of exploitation (screenshots, evidence)
- Reproduction steps (payloads, code, commands)
You must comply with all testing policy rules.
You must not be a current or former employee or contractor of ExpressVPN.

Reward amounts depend on:

Reward grid of the relevant scope
CVSS score and risk impact analysis

Reward

Asset value	CVSS Low	CVSS Medium	CVSS High	CVSS Critical
High	$200	$600	$1,250	$2,500

Scopes

Scope	Type	Asset value
*.expressvpn.com	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
expressvpn.jobs	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
ExpressVPN APIs	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://xv-cp.apis-staging.xvtest.net/	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://cp.expressapisv2.net	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://api.expressvpn.com	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://api.enc.kape.com	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://api.dbs.kape.com	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://api.dts.kape.com	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://api.blts.kape.com	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://api.pcrs.kape.com	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://api.jwks.kape.com	API	High
Low $200 Medium $600 High $1,250 Critical $2,500
VPN servers	Other	High
Low $200 Medium $600 High $1,250 Critical $2,500
ExpressVPN Router	Other	High
Low $200 Medium $600 High $1,250 Critical $2,500
*.xvtest.net	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
*.xvservice.net	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
it.xvservice.net	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
1pw-scim.prd.iat.it.xvservice.net	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
gatekeeper.prd.iat.it.xvservice.net	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
iat.it.xvservice.net	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
prd.iat.it.xvservice.net	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
vector.prd.iat.it.xvservice.net	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
gh-mail.expressvpn.com	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
*.polymoon.it	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
corp.polymoon.it	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
networkguard.com	Web application	High
Low $200 Medium $600 High $1,250 Critical $2,500
Any Applications under https://www.expressvpn.com/latest	Application	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://github.com/expressvpn/lightway-core	Other	High
Low $200 Medium $600 High $1,250 Critical $2,500
https://github.com/expressvpn/lightway	Other	High
Low $200 Medium $600 High $1,250 Critical $2,500

Out of scopes

All domains or subdomains not listed in the above list of 'Scopes'

Vulnerability types

Qualifying vulnerabilities

SQL Injection (SQLi)

Cross-Site Scripting (XSS)

Remote Code Execution (RCE)

Insecure Direct Object Reference (IDOR)

Horizontal and vertical privilege escalation

Authentication bypass & broken authentication

Business Logic Errors vulnerability with real security impact

Local files access and manipulation (LFI, RFI, XXE, SSRF, XSPA)

Cross-Origin Resource Sharing (CORS) with real security impact

Cross-site Request Forgery (CSRF) with real security impact

Open Redirect

Exposed secrets, credentials or sensitive information on an asset under our control and affecting at least one of our scopes

Cross-site Request Forgery (CSRF) with real security impact

Remote silent installation of any app

Other severe logic vulnerabilities that can be exploited remotely

Privilege escalation vulnerabilities

Vulnerabilities able to break the site isolation restrictions of a browser

Arbitrary code execution or silent installation by staging MITM attacks

Stealing of sensitive information by staging MITM attacks

UI deception vulnerabilities that may cause actual harm

Non-qualifying vulnerabilities

Broken Link/Social media Hijacking

Tabnabbing

Missing cookie flags

Content/Text injections

Clickjacking/UI redressing

Denial of Service (DoS) attacks

Recently disclosed CVEs (less than 14 days since patch release)

CVEs without exploitable vulnerabilities and PoC

Open ports or services without exploitable vulnerabilities and PoC

Social engineering of staff or contractors

Presence of autocomplete attribute on web forms

Vulnerabilities affecting outdated browsers or platforms

Self-XSS or XSS that cannot be used to impact other users

Any hypothetical flaw or best practices without exploitable vulnerabilities and PoC

SSL/TLS issues (e.g. expired certificates, best practices)

Unexploitable vulnerabilities (e.g. Self-XSS, XSS or Open Redirect through HTTP headers...)

Reports with attack scenarios requiring MITM or physical access to victim's device

Missing security-related HTTP headers which do not lead directly to an exploitable vulnerability and PoC

Low severity Cross-Site Request Forgery (CSRF) (e.g. Unauthenticated / Logout / Login / Products cart updates...)

Invalid or missing email security records (e.g. SPF, DKIM, DMARC)

Session management issues (e.g. lack of expiration, no logout on password change, concurrent sessions)

Disclosure of information without exploitable vulnerabilities and PoC (e.g. stack traces, path disclosure, directory listings, software versions, IP disclosure, 3rd party secrets, EXIF Metadata, Origin IP)

CSV injection

Malicious file upload (e.g. EICAR files, .EXE)

HTTP Strict Transport Security Header (HSTS)

Subdomain takeover without a full exploitable vulnerability and PoC or not applicable to the scope

Blind SSRF without exploitable vulnerabilities and PoC (e.g. DNS & HTTP pingback, Wordpress XMLRPC)

Lack or bypass of rate-limiting, brute-forcing or captcha issues

User enumeration (e.g. email, alias, GUID, phone number, common CMS endpoints)

Weak password policies (e.g. length, complexity, reuse)

Ability to spam users (email / SMS / direct messages flooding)

Disclosed or misconfigured public API keys (e.g. Google Maps, Firebase, analytics tools...)

Password reset token sent via HTTP referer to external services (e.g. analytics / ads platforms)

Stolen secrets, credentials or information gathered from a third-party asset that we have no control over

Exposed secrets, credentials or information on an asset under our control that are not applicable to the program’s scope

Pre-account takeover (e.g. account creation via oAuth)

GraphQL Introspection is enabled

Crashing your own application

Google API Keys (eg. Analytics, Maps)

Lack of code obfuscation / binary protection

Exploiting a generic Android or iOS vulnerability

Information requiring physical access to user device

Exploits that are only possible on rooted/jailbroken device

Exploits that are only possible on iOS version 16 and below

Exploits that are only possible on Android version 14 and below

Lack of encryption on internal databases/preference files on mobile device

Vulnerabilities affecting outdated application binaries - only exploits working on latest Android/iOS versions from the respective app stores will be accepted

Lack of client-side protections on mobile binaries: SSL pinning/binary protection/code obfuscation/jailbreak detection/root detection/anti-debugging controls/ etc

Hunting requirements

Account access

ExpressVPN Public-Facing Scope

You may create ExpressVPN accounts by signing up to a 7-day free trial by signing up with our Android or iOS applications. Alternatively, you can sign up for a regular account and make use of our 30-day money-back guarantee here https://www.expressvpn.com/order.
- Please use your YesWeHack email aliases which are available here for account creation.
The use of a personal account is authorized if you have one.

Restricted access

Please note: Some in-scope assets may only be accessible to authorized or authenticated users. No additional credentials or privileged access will be provided as part of this program. Researchers are expected to focus on unauthenticated attack surfaces or responsibly identify authentication-related issues using public-facing functionality.

Hunters collaboration

When submitting new report, you can add up to 5 collaborators, and define the reward split ratio.

For more information, see help center.
Note: For reports that have already been rewarded, it is not possible to redistribute the rewards.

To submit a vulnerability report, you need to login with your hunter account.