Bitcoin Core 31.0 Privacy Bug Risks IP Leaks via v2 Handshake Fallback

Bitcoin Core developers disclosed a privacy flaw in the optional -privatebroadcast feature of version 31.0 on June 12. The bug allows malicious peers to force a fallback from BIP324 v2 to v1, bypassing Tor and exposing node operators' real IP addresses. The issue affects only users who enabled the feature and does not impact miners or regular wallet users. A fix is scheduled for Bitcoin Core 31.1, with developers advising immediate disablement or full Tor routing. Bitcoin traded little changed near $63,700, indicating limited market reaction to the security disclosure.