From Decrypt · By André Beganski
In brief
Longtime Bitcoin developer and BIP-54 co-author Matt Corallo says there’s an 80% chance the “Great Consensus Cleanup,” first proposed in 2019, will be Bitcoin’s next soft fork—a practical fix for issues “everyone agrees are problems.”
The upgrade targets four lingering vulnerabilities: poison blocks, time warp bugs, Merkle malleability and duplicate coinbase transactions—none urgent, but real.
Critics like LayerTwo Labs’ Paul Sztorc call it “depressing” janitorial work.
Four flaws in Bitcoin’s consensus rules that have lingered for years.
Issues like quantum resistance may command attention, but a practical cleanup is what many experts think Bitcoin’s next soft fork is likely to address, spanning fixes for vulnerabilities in the network’s difficulty adjustment mechanism to denial-of-service vectors among miners.
Proposed in 2019 and known as the Great Consensus Cleanup (BIP-54), the upgrade seeks to address the “cruft” in Bitcoin’s consensus design through changes that have historically been sidelined, as described by long-time Bitcoin developer and BIP-54 co-author Matt Corallo.
PredictCryptoBTC Highs in November
80,00050%YesNo82,50080%YesNo85,00057%YesNo87,50038%YesNo90,00025%YesNo+6 more outcomes+5 more outcomesNEW$96.13 volumeCloses: Dec 1, 2026, 04:59 UTCCloses: Dec 1, 2026, 04:59 UTC“There’s a laundry list of things we know of that we really need to clean up,” he said during a recent appearance on MARA Foundation TV. “All of these issues are real concerns that could impact Bitcoin negatively, but they’re not like, ‘Oh, the sky is falling.’”
Although a formal timeline for the BIP’s undertaking hasn’t been established, Corallo thinks there’s an 80% chance that the Great Consensus Cleanup is up next for the network. During his talk with Head of MARA Foundation Isabel Foxen Duke, he also called it a practical exercise for Bitcoin developers who haven’t yet been through a soft fork.
At its core, Corallo said BIP-54 “fixes some stuff that everyone agrees are problems,” while targeting four specific vulnerabilities:
Poison blocks: If a miner wanted to gain a temporary advantage over competitors, they could mine a specially crafted block that exploits performance bottlenecks, intentionally slowing down node validation for everyone else.
Time warp bugs: A loophole in Bitcoin's two-week difficulty adjustment window allows miners controlling a majority of hashrate to manipulate block timestamps, artificially accelerating the rate at which new blocks are issued.
Merkle malleability: Because a 64-byte transaction happens to be the exact same data size as an internal Merkle tree node, an attacker can theoretically forge proofs to trick light clients into accepting fake transactions.