Security Flaws Found in 99 Percent of x402 Payment Facilitators

A new security report highlights 31 vulnerabilities affecting 15 major x402 payment facilitators. The study shows that these facilitators, which account for nearly all observed x402 transactions, failed to meet basic verification standards. These gaps create risks for both merchants and users, including the possibility of service theft and unexpected gas costs.

These findings identify four main attack types. Attackers could potentially access services without paying, drain funds from facilitators, jam payment systems, or force facilitators to pay for malicious transaction fees. While the research demonstrated two cases of free shopping, no actual theft of funds took place during the testing process.

It is important to note that these findings do not mean the x402 protocol itself was breached. The issues lie with the middle layer facilitators that verify payments for merchants. As of February, several companies including Coinbase have acknowledged the report and begun implementing fixes to address these weaknesses.

Experts recommend that merchants wait for full payment settlement before releasing services to prevent exploitation. Moving forward, the industry must focus on stricter verification and better control over how intermediaries handle payment proofs. Users and developers should watch for updates from these service providers as they roll out patches to close these security gaps.