Beam, the privacy coin implementing the MimbleWimble protocol, announced via its Twitter that Beam’s blockchain stopped at block 25,709 and that the team is investigating and will release an update. Two hours later, Beam tweeted that the issue was identified and a fix was found. It also reassured the Beam holders that the funds are safe. A little more than an hour later, the Beam team committed the fix on Github.
The binaries were released some time later here. The blog post described the bug as a “rare scenario [that] resulted from the untypical (yet valid), wallet usage pattern which caused the nodes to fail to mine the next block after height 25709.” The fix was applied to the flaw in the block construction code, which generated a wrong commitment to the UTXO state. Two weeks ago, Beam found a critical vulnerability in the Beam Wallet. The issue was fixed by uninstalling the wallet and reinstalling the patched version.