LND release candidate caps external fee estimates for node wallets
LND's 0.21.5 release candidate adds a ceiling on fee values received from external APIs, addressing a wallet risk in node software.
The Lightning Network Daemon's latest release candidate, version 0.21.5, introduces a guardrail for fee estimates pulled from outside APIs, according to the project's development notes dated October 22.
The change places a ceiling on values accepted through an external fee API. That limits how much weight the software gives to fee data supplied by a third party, which the notes identify as a source of wallet risk when estimates are accepted too readily.
Why external fee inputs matter
Lightning nodes rely on fee estimates for on-chain transactions such as channel opens, closes and sweeps. If an outside API returns an unusually high number and the software accepts it without a bound, a node operator could pay more than intended.
The same release candidate also includes fixes to other node operations, though the available summary does not provide a full breakdown of every change. The update remains a release candidate, meaning it is still undergoing testing before a final release.
LND is one of the main implementations of a Bitcoin Lightning node. Guardrails around external data fit a broader pattern of node software tightening assumptions about third-party inputs, but the practical effect will depend on how operators configure their nodes.