Core Lightning (CLN) developers have informed node operators to take their nodes offline due to a critical and unpatched vulnerability. CLN is one of the main implementations of the Bitcoin Lightning Network, and if the vulnerability is exploited before the patched version is deployed, it could put user funds at risk. The patched binary has not yet been released, and the team has not disclosed details citing a two-week confidentiality period. Operators unable to upgrade can run their nodes using the --offline flag.