Hack history / 2026 / Hack or exploit
Fractal Protocol
Hack or exploit on May 22, 2026 · Reentrancy
ATTACK TX CONFIRMED ON CHAINSOURCES AGREE ON DATE AND LOSS · 3 SOURCES
Lost
$14K
dollars at the time
Returned
none listed
as the sources state it
Rank
#2,203
among thefts by dollars lost
What happened
Fractal Protocol's USDF vault on Arbitrum was drained of 13,700 USDC.e via re-entrant flashloan attack. The attacker looped through Balancer V2 batchSwap callbacks to recursively call the vault's deposit and withdraw functions. The vault's tokenPrice accrued only once daily and its share arithmetic rounded favorably for the depositor, allowing each re-entrant round-trip to extract more than it put in.
Details
- Date
- May 22, 2026
- Kind
- Hack or exploit
- Method
- Reentrancy
- How in
- Smart contract bug
- Target
- DeFi protocol
- Chains
- Arbitrum
Reported by
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Cite this page
SwanBluechip, "Fractal Protocol hack, May 22, 2026: $14K lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht21b386ab63/ (data as of 2026-11-01).