ACINQ Patched Eclair to Prevent Excess Mining Fees
The update prevents nodes from being forced into high-cost transactions by malicious peers in dual-funded channels.
Updated on Oct. 12, 2026 in Quantum Computing
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ACINQ has merged two fixes into the Eclair master branch to protect network nodes from excessive Bitcoin mining fees. These changes, implemented in October 2026, defend against potential manipulation in dual-funded channels.
Why it matters
The fixes secure the Eclair Lightning implementation against potential fee-draining attacks where peers might impose arbitrary costs on node operators. This update ensures that transaction fees are strictly verified against local calculations rather than trusting inputs from remote counterparts.
Eclair v0.14.3 introduced new logic to reject replacement transactions that exceed a node's maximum recommended funding fee rate. In signer mode, the software now independently calculates fees based on inputs and outputs to match them against values reported by Bitcoin Core.
The players
ACINQ
A developer of the Lightning Network infrastructure that maintains the Eclair software and operates a major Lightning routing node.
The details
The fixes target vulnerabilities within dual-funded channels—a mechanism allowing multiple parties to contribute funds to a single Lightning payment channel. The Eclair-signer mode—a specialized configuration that separates the private key operations from the networking logic—now performs a checksum-like verification of fees. By comparing actual transaction data against figures provided by Bitcoin Core, the node prevents the execution of funding transactions that carry unauthorized mining premiums.
Timeline
September 14, 2026: Eclair v0.14.3 was released.
October 2, 2026: The first fee-limiting fix was merged into the Eclair master branch.
October 5, 2026: The second fee-verification fix was merged into the Eclair master branch.
The Tech Race
The development updates the security posture of the Eclair Lightning implementation relative to the broader Lightning Network protocol. It ensures nodes remain competitive by preventing potential drainage of liquidity through fee manipulation.
Node operators running Eclair should ensure they are updated to version 0.14.3 or newer to benefit from the new fee-verification logic. These protections are active by default for users utilizing dual-funded channels once the code is integrated into their production environment.
The takeaway
The update mitigates a specific class of fee-based attack vector for Lightning nodes. Operators should verify that their implementation tracks these upstream master branch merges to ensure ongoing protection against malicious channel counterparty behavior.
Further reading
For broader context on node security and payment channel infrastructure, visit the Quantum Computing section.
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Do you trust current cryptocurrency software to automatically protect your funds from excessive transaction fees?
