BTCPay Server, a self-hosted, open-source cryptocurrency payment processor, has urged users to install the latest version of its software in response to reports of Bitcoin and Litecoin being stolen from hot wallets on instances running older versions.
“Our investigation found that these attacks targeted servers running BTCPay Server 2.4.1 (released on 23 July 2026) or earlier,” BTCPay Server said. “The attackers used a different method to exploit the vulnerability fixed in 2.4.2, released on 7 August 2026.”
Users running version 2.4.1 or earlier are recommended to move to a fresh server with a new wallet, even in scenarios where no theft has been noticed. In the event of stolen funds or suspected unauthorized access, users should consider the entire machine and all secrets stored on it as compromised and follow the same recovery procedures.
It is currently unknown when the attackers behind the campaign first began exploiting the vulnerability, although reports began to surface around November 1, 2026.
In a post on X, BTCPay Server said no “credible reports” of hot wallet drains have been reported from users running the latest 2.4.7 release. That version addresses one critical and several medium-severity security vulnerabilities discovered via Anthropic’s OSS scanner.
BTCPay Server has also shared two wallet addresses linked to these incidents:
- Bitcoin: bc1p0f7wmcnesrapznymf9ljdn04pudgmh96sqtrm9vmgqxdh666fh8qvn63r7
- Litecoin: ltc1qp49tmfdueyaqrmgrx0uyx4uegyygt8yt02whee
“If you need a hot wallet for daily operations, keep only the funds needed for those operations on the server and move the rest to a wallet whose spending keys are held off the server,” the project cautioned.
“If you run BTCPay Server through a hosting provider, your instance may have been shut down automatically to keep older versions from being exploited.”
In August 2026, BTCPay Server disclosed that a critical vulnerability had been weaponized by attackers to steal funds from some users. The issue, which affects all BTCPay Server versions, was patched in version 2.4.2. It is unclear whether the latest set of attacks is related to the same vulnerability.
“The issue could allow an unauthenticated remote attacker to obtain .macaroon credential files for LND, an implementation of the Lightning Network,” BTCPay Server said in the August alert. “Those credentials could be used to take control of an LND node and move funds. The attacks we reviewed targeted only files with the .macaroon extension.”
The development coincides with a string of security breaches and exploits across the cryptocurrency space, including the record theft of $6.43 billion from Binance by North Korean threat actors. That same day, prediction market giant Polymarket briefly halted trading after a $2.65 million exploit following the compromise of software developed by DebugBear.
Hardware wallet maker Trezor also issued a warning after receiving a responsible disclosure report alleging a hardware implant in a Trezor Safe 5 purchased from CryptoBilis in August 2026. The incident is assessed to be part of a sophisticated supply chain attack in which devices sold via third-party resellers are physically tampered with to steal the victim’s seed phrase and drain their assets.
Mercado Bitcoin Discloses Security Incident
Brazil’s largest cryptocurrency exchange, Mercado Bitcoin, announced it is temporarily pausing deposits and withdrawals following a security breach that resulted in $49 million in stolen funds.
“At this moment, the value of the assets involved is approximately $38 million,” the exchange said on X. “In a swift action with the crypto community and strategic partners — including Tether, Circle, Paxos, BRL1, and Chainalysis — we have already blocked US$11 million.”
The exchange added that additional amounts eligible for blocking have been identified and that containment efforts are ongoing. Services will resume once full security conditions are met, with updates to be communicated through official channels.
Tether CEO Paolo Ardoino confirmed that the stablecoin issuer had frozen more than 4.5 million USDT in connection with the incident.
