YFI drops 11.48% over the past month following a significant security incident

Yearn Finance Faces Major Setback After yETH Pool Exploit

On December 2, 2025, Yearn Finance’s YFI token experienced a significant downturn, dropping 5.22% in the past 24 hours. This decline contributed to an 11.12% loss over the previous week and an 11.48% decrease in the last month. Compared to the same period last year, YFI has lost 54.2% of its value. These losses come in the wake of a major security breach involving the yETH stableswap pool, which has sent shockwaves through the DeFi community.

Details of the Security Breach

On November 30, Yearn Finance revealed that a critical vulnerability in its legacy yETH stableswap pool had been exploited. Attackers took advantage of a subtle arithmetic error in the pool’s custom code, allowing them to mint a large amount of yETH in a single transaction and siphon off funds. In total, $8.9 million was stolen—$8 million from the yETH stableswap pool and another $900,000 from the yETH–WETH pool on Curve. This incident stands out as one of the most significant DeFi security breaches in recent memory, highlighting the dangers of outdated smart contracts.

Ongoing Recovery Efforts

In response to the exploit, Yearn Finance quickly partnered with security experts SEAL 911 and ChainSecurity to limit further losses. By December 1, the team, working alongside Plume and Dinero, managed to recover $2.39 million, including 857.49 pxETH. These funds will be returned to affected users as the recovery process continues.

Yearn Finance has assured users that its V2 and V3 vaults—which collectively hold over $600 million—were not impacted by the attack and continue to operate on separate, unaffected codebases. The protocol is now conducting an in-depth investigation with its auditing partners and has encouraged those affected to reach out through the Yearn Discord channel for support.

Wider Implications for DeFi Security

This exploit is the latest in a string of high-profile security incidents within the DeFi sector. In late November, both Prisma Finance and Raft Finance suffered losses due to compromised keys and vulnerabilities in their contracts. Earlier in the year, Curve Finance was also targeted, with attackers exploiting a flaw in the Vyper compiler. These events underscore the persistent risks associated with legacy smart contract infrastructure.

Yearn Finance has stated that it is actively reviewing older contracts to strengthen security and prevent similar incidents in the future. Industry analysts point out that such breaches continue to challenge investor trust in DeFi platforms, as reflected in YFI’s steep price drop.

Market Response to the Incident

The YFI token saw a rapid decline of about 10% following news of the exploit. Although the initial sell-off raised concerns about the protocol’s stability, the partial recovery of stolen funds has provided some reassurance to the community. At the time of writing, YFI was trading at $3,686.

This episode highlights the critical need for strong security measures in decentralized finance. As Yearn Finance works to rebuild confidence and stabilize its platform, the broader crypto market remains attentive to future developments and the potential long-term effects on YFI’s value.