LND Tests A Guardrail Against Extreme External Bitcoin Fee Estimates

LND’s October 22 release candidate brings attention to a quiet source of wallet risk: outside fee estimates that software treats too generously. The 0.21.5 development notes describe a ceiling for values received through an external fee API, alongside fixes to other node operations. The release notes say external estimates previously had a lower bound without the corresponding upper bound. The documented repair limits the estimate before it can flow into fee-sensitive wallet operations. The associated change applies a ceiling of 10,000 satoshis per virtual byte and also bounds the API’s minimum-relay estimate. That ceiling is an extreme-value guardrail.