Share this article
Bug Found in Decoy Algorithm for Privacy Coin Monero
"This does not reveal anything about addresses or transaction amounts ... This bug persists in the official wallet code today," Monero said.
Updated Sep 14, 2021, 1:31 p.m. Published Jul 27, 2021, 6:36 a.m.
A "significant" bug, with the potential to expose users' transactions, has been spotted in monero, a cryptocurrency that's known for providing users privacy, according to a Twitter post on Tuesday.
Don't miss another story.Subscribe to the Crypto Daybook Americas Newsletter today. See all newsletters
- The bug was identified in Monero's decoy selection algorithm. It occurs when a user spends their funds received in a transaction before roughly 20 minutes has passed.
- There is a "good probability" the output of the new transaction can be identified as the true transaction, according to the tweet.
- XMR allows users to conceal their transactions by including worthless coins known as “mixins” along with the actual coins they spend in a given transaction.
- "This does not reveal anything about addresses or transaction amounts ... This bug persists in the official wallet code today," Monero said.
- Users may avoid the bug altogether by waiting one hour or more before spending their newly received monero until a fix is implemented in a future wallet software update.
- A hard fork is not required to fix the bug, Monero said.
- U.S. software developer Justin Berman first spotted the bug.
Read more: Monero-for-Bail Project Sees Increased Demand During Protests
More For You
Protocol Research: GoPlus Security

What to know:
- As of October 2025, GoPlus has generated $4.7M in total revenue across its product lines. The GoPlus App is the primary revenue driver, contributing $2.5M (approx. 53%), followed by the SafeToken Protocol at $1.7M.
- GoPlus Intelligence's Token Security API averaged 717 million monthly calls year-to-date in 2025 , with a peak of nearly 1 billion calls in February 2025. Total blockchain-level requests, including transaction simulations, averaged an additional 350 million per month.
- Since its January 2025 launch , the $GPS token has registered over $5B in total spot volume and $10B in derivatives volume in 2025. Monthly spot volume peaked in March 2025 at over $1.1B , while derivatives volume peaked the same month at over $4B.
More For You
Coinbase Sees Crypto Recovery Ahead as Liquidity Improves and Fed Rate Cut Odds Climb

The crypto exchange also took note of a so-called AI bubble that continues to go strong and a weaker U.S. dollar.
What to know:
- Coinbase Institutional is seeing a potential December recovery in crypto, citing improving liquidity and a shift in macroeconomic conditions that could favor risk assets like bitcoin.
- The firm's optimism is driven by rising odds of Federal Reserve rate cuts, with markets pricing in a 93% chance easing next week, and improving liquidity conditions.
- Several recent institutional developments, including Vanguard's crypto ETF policy reversal and Bank of America's greenlighting of crypto allocations, have contributed to bitcoin's rebound from recent lows.
Top Stories












