Fence Finance Tranche Vault Share Inflation

Summary

A flash-loan attacker inflated vault share accounting to drain about 1.01 million USDC from an Avalanche Tranche Vault linked to Fence Finance and Valinor Digital.

Incident

• Victim: Fence Finance
• Date (UTC): 2026-10-27
• Estimated loss: $1.0M
• Chain(s): Avalanche
• Attack type: flash-loan exploit
• Funds status: stolen

Recommended actions

• Revoke token approvals granted to Fence Finance contracts until the project confirms they are safe
• Integrators: pause or delist affected assets and monitor for attacker fund movements
• Beware of follow-on phishing: ignore unofficial "refund", "recovery", or "claim" links and DMs; use the project's verified channels only

Source & attribution

Full analysis on Blockchain Breaches, 0xCERT's incident archive: https://www.blockchainbreaches.com/en/breaches/fence-finance-2026. Primary sources: https://unchainedcrypto.com/flash-loan-attacker-drains-about-1-million-in-usdc-from-avalanche-based-tranche-vault/ ; https://www.cryptotimes.io/2026/10/28/avalanche-vault-hack-1-01m-usdc-drained-in-flash-loan-exploit-tied-to-valinor-and-fence/ ; https://en.coin-turk.com/attacker-drains-1-01-million-in-usdc-from-avalanche-tranche-vault-using-flash-loan/ ; https://www.kucoin.com/news/flash/hackers-steal-1-01m-from-tranche-vault-on-avalanche.