Hack history / 2025 / Hack or exploit
Yearn Ether
Hack or exploit on Dec 1, 2025 · Incorrect Share Accounting
SOURCES AGREE ON DATE AND LOSS · 5 SOURCES
Lost
$9M
dollars at the time
Returned
$2.4M
27% of the loss, as a source states it
Rank
#322
among thefts by dollars lost
What happened
Yearn Finance yETH stableswap pool drained for $9M on deposit of 16 wei. Attacker minted 235 septillion yETH via accounting flaw caused by cached storage variables not resetting at zero liquidity, then swapped for legitimate derivatives.
Details
- Date
- Dec 1, 2025
- Kind
- Hack or exploit
- Method
- Incorrect Share Accounting
- How in
- Smart contract bug
- Target
- DeFi protocol
- Chains
- Ethereum
After the theft
- Recovered or seized
- yes, amount not stated
“On December 1, according to PeckShield’s monitoring, Yearn recovered 2.4 million USD by burning the pxETH held by the hacker.” (SlowMist Hacked) - Returned by the attacker
- yes, amount not stated
“An equivalent amount of pxETH has been re-minted and returned to the Redacted Cartel multisig wallet.” (SlowMist Hacked) - Recovered or frozen
- $2.4M
“$9.0M taken, $6.6M after recovery or freezing” (Web3 Is Going Great)
Related incidents
ether.fi Liquid 2026 · Hack or exploit · $43K
Yearn Finance 2025 · Hack or exploit · $300K
ether.fi 2025 · Fraud · undisclosed
"On-chain Microstrategy" clone Ether Strategy loses over $500,000 of ETH 2025 · Costly mistake or other · $536K
ether.fi 2024 · Hack or exploit · undisclosed
Yearn Finance 2025 · Hack or exploit · $300K
ether.fi 2025 · Fraud · undisclosed
"On-chain Microstrategy" clone Ether Strategy loses over $500,000 of ETH 2025 · Costly mistake or other · $536K
ether.fi 2024 · Hack or exploit · undisclosed
Cite this page
SwanBluechip, "Yearn Ether hack, Dec 1, 2025: $9M lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/htddd3191ae5/ (data as of 2026-10-31).