rewrite this title Bitcoin Payment Service BTCPay Warns Critical Flaw Is Under Active Attack – Decrypt

BTCPay Server warned users Friday that attackers are exploiting a critical vulnerability that could lead to stolen funds.

In a post on X on Friday, the Bitcoin payment processor urged administrators to install version 2.4.2 and confirm the update in the server footer.



“If you are unable to update right away, turn off your BTCPay Server to prevent unauthorized access until you can update,” the company wrote.

BTCPay Server also told users to replace credentials known as macaroons and recreate the macaroons.db file and refresh authentication strings for other Lightning Network backends.

“If you generated a hot on-chain wallet in BTCPay, you want to move those funds and recreate the wallet,” they added.

The project credited Bitcoin Red Team members with reporting the vulnerability.

BTCPay Server has not disclosed how the flaw works, when the attacks began, how many servers were compromised, or whether any funds were actually stolen.

While BTCPay Server did not disclose whether AI played a part, the news comes as AI is increasingly finding flaws in crypto projects.

In May, security researcher Taylor Hornby used Anthropic’s Claude Opus 4.8 to find a four-year-old Zcash vulnerability that could have allowed attackers to create unlimited counterfeit ZEC.

In August, Coldcard maker Coinkite said it suspected attackers used AI to find a firmware flaw linked to more than $100 million in stolen Bitcoin.

More recently, on Tuesday, Bitcoin swap provider Boltz suspended its service after several exploits, saying AI-assisted attacks were finding vulnerabilities faster than its team could fix them.

BTCPay Server did not immediately respond to a request for comment by Decrypt.