Hack history / 2021 / Hack or exploit
PolyYeld Finance
Hack or exploit on Jul 28, 2021 · Infinite Mint
SOURCES AGREE ON DATE AND LOSS · 2 SOURCES
Lost
$250K
dollars at the time
Returned
none listed
as the sources state it
Rank
#1,396
among thefts by dollars lost
What happened
On July 28, 2021, PolyYeld Finance was exploited when attackers discovered that the Masterchef contract could not properly handle xYELD's transfer tax reward distribution system. Attackers minted approximately 4.995 billion YELD tokens and converted 4% of them to ~123 ETH (~$250K) before the token crashed 100%.
Details
- Date
- Jul 28, 2021
- Kind
- Hack or exploit
- Method
- Infinite Mint
- How in
- Smart contract bug
- Target
- DeFi protocol
- Chains
- Polygon
Reported by
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Acala Network 2021 · Hack or exploit · $1.6M
Cite this page
SwanBluechip, "PolyYeld Finance hack, Jul 28, 2021: $250K lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht905ab999c2/ (data as of 2026-11-01).