Core Lightning warns to disable experimental features on nodes

Core Lightning developers have warned anyone running experimental features on their software to disable them or risk losing their funds while the team figures out a recently discovered issue.

The mid-September warning is the second in a matter of weeks, following a late August patch to fix a separate wave of bugs that could have affected businesses, payment providers, and individual operators using Core Lightning’s (CLN) software packages to operate nodes on Bitcoin’s Lightning Network.

The current advisory does not apply to Bitcoin’s main network.

New risk warning for Core Lightning node operators 

Core Lightning issued a new risk alert on September 15, urging operators to disable any experimental features they have enabled immediately.

Core Lightning did not explain what the experimental feature does or how it could be exploited.

However, the fund loss headache is real as these nodes hold BTC inside payment channels and route funds between users.

Before this September warning, CLN was trying to move on from an eventful August caused by a high volume of AI-generated CVE reports.

The instruction then was to restart nodes with the –offline flag, which cuts peer connections so no payments route through while the software keeps watching the chain.

By August 28, the CLN team told node operators that upgrading to version 26.06.7 was the fix to the issues that emerged during the month. 

The technical details of that fix were released to GitHub on September 11 after the two-week embargo expired on the period during which attackers could reverse-engineer the patches. 

AI tools have become a problem for pen-source Bitcoin

The Lightning Development Kit, a separate Lightning Network implementation, faced its own security emergency in August, reinforcing a developing pattern where AI tools are being used to scan open-source Bitcoin code for security flaws. 

LDK’s maintainers reported no observed losses or exploited applications.

The smartest crypto minds already read our newsletter. Want in? Join them.