Zerodium an exploit purchase agency announced that it’s looking to buy zero-day exploits targeting popular VPN software. Specifically wants to acquire exploits that work against the Windows versions of the ExpressVPN, NordVPN and Surfshark applications. These VPN services have millions of users.

Zerodium is looking for remote code execution, IP address leak, and other information disclosure exploits. It does not want to acquire local privilege escalation vulnerabilities.

ExpressVPN and NordVPN both run bug bounty programs. ExpressVPN offers up to $2,500 per vulnerability with bonuses of up to $10,000, while NordVPN offers $5,000 or more for critical security flaws. Zerodium is likely prepared to pay out much more for zero-day exploits.

ExpressVPN, NordVPN and Surfshark are mostly used by consumers and there aren’t any reports of vulnerabilities in these applications being exploited in attacks.

There are many reports of enterprise VPN solutions being targeted by threat actors, particularly products made by Fortinet, Pulse Secure, Citrix, VMware, and Zimbra. The NSA issued an alert earlier this year, warning organizations that vulnerabilities in these products had been exploited by Russian spies.

Zerodium is temporarily offering higher bounty for Chrome, VMware vCenter Server, and WordPress exploits. The company is offering up to $1 million for Chrome, $150,000 for vCenter Server, and $300,000 for WordPress exploits.