Critical Bug Report and Response
On March 18, 2021, a GRIN developer contacted the MWC development team with a critical bug report related to the rangeproof caching logic. The GRIN developers recommended not using the network until a fix had been safely implemented. Read more on the GRIN forum.
MWC exchanges were immediately notified about this critical bug and requested to halt trading, deposits, and withdrawals.
Implementation of the Fix
The GRIN network was affected and a fix was implemented with a rewind of the blockchain. Details of the fix.
Unfortunately, these types of unexpected events have happened in Bitcoin and other distributed consensus networks. List of Bitcoin forks.
Because MWC is a fork of GRIN, it therefore contained the same bug. The MWC development team is implementing a similar fix; however, it may take slightly longer to take complete effect. The rewind will take place at block 693,000 which was on March 13th. Any transactions before that block will be unaffected.
Recommendations and Next Steps
Consequently, following the example of the GRIN developers, the MWC developers recommend not using the MWC network until a fix has been safely implemented. The rewind is expected to affect about six days of the blockchain. The plan is for legitimate transactions, to the extent possible, to be included so end users are not significantly affected.
The fix, rewind, testing, and implementation are expected to take a few days. Users will be able to download an updated version of the wallet to get the rewind to take effect sooner. After that, it may take up to a week for users with non-upgraded nodes to get a correction to their transaction history.
We salute all of the warriors for monetary sovereignty and finding and fixing these bugs. This is hard work!
For more information, visit MWC Critical Bug Report.
