Cosmos EVM Flaw Drains Funds From Six Blockchains
Cosmos (ATOM)
Editor:
Eugene Serbin
Cosmos Labs warned that a critical balance-handling flaw in the shared Cosmos EVM module was exploited to drain funds from six blockchains between August 20 and August 25, 2026. The vulnerability, designated GHSA-7g4w-cg88-2cq2, was reported via the bug bounty program on April 25 but was initially assessed as posing no risk to live networks. The team incorrectly concluded the issue affected only non-18-decimal networks, yet confirmed by August 13 that all Cosmos EVM chains were affected regardless of decimal configuration.
The flaw resides in the code reconciling EVM state with the Cosmos SDK x/bank module, allowing an unchecked subtraction that wraps the balance to roughly 2^256. Attackers exploited this by moving finite amounts out of wrapped accounts or sending victims a large sum to trigger a burn of their real holdings. The fix shipped in v0.6.2 and v0.7.2 on August 19 but was distributed through a public silent patch process rather than private secure channels.
Cosmos Labs stated, "We were unable to reproduce the vulnerability on 18-decimal networks and incorrectly concluded that it affected only non-18-decimal networks." The company noted that for a flaw threatening user funds, they typically use secure channels, but proceeded with the silent patch because the fix was already public on the main branch. The Hacker News confirmed that neither release lists the pull requests carrying the fix in their changelogs. Operators are advised to upgrade to the fixed versions or halt the chain immediately to prevent further exploitation.
How the market reacted
Whalio's own Binance spot order flow for ATOM, measured when this story was written up on 29 August 2026. Not the outlet's figures.
ATOM is trading at $1.48 with a 24-hour buy ratio of 48.6%, indicating a near-even split between buyers and sellers. The 1-hour buy ratio has dropped to 31.9%, suggesting that short-term buying pressure is fading compared to the daily average. Volume Delta shows -$20,960 in the last hour and -$67,812 over 24 hours, meaning sell volume has exceeded buy volume recently. The 4-hour buy ratio sits at 51.6%, showing that buying pressure was stronger in the immediate past hour than it is now. CVD closed at -$31,619, reflecting that net selling has outweighed net buying over the day. Spot volume reached $2,520,595 with 18,359 trades, showing active but balanced market participation.
The latest daily buy ratio of 44.7% sits at the 9th percentile of the last 322 days, against a median of 49.8% - among the weakest buying days it has had.
Twenty-four hours later
What ATOM did over the 23 hours after the story broke. The market moves for its own reasons; this is what happened, not what the story caused.
Was that an ordinary day?
The same Binance spot measurements for ATOM, averaged over the days leading up to the story.
Over the preceding week, ATOM experienced a 7.5% price decline with volume at 0.84x the average. The 7-day average buy ratio was 51.6%, while the latest day was 3.0 percentage points lower, indicating a slight shift toward selling. Net buying occurred on 5 of the last 7 days, with a total Volume Delta of +$468,398 for the period. This suggests that while the weekly trend was net positive, today's activity is less bullish than the weekly average. The current day represents a deviation from the week's generally positive flow, with lower volume and reduced buying pressure.