Raydium Legacy AMM V3 Exploited for $1.34M via LP Mint Flaw

Raydium's Legacy AMM V3 protocol suffered a $1.34M exploit through an LP mint validation flaw that allowed an attacker to bypass proportion checks in deprecated pools. The attacker created a fake LP mint to drain five idle pools, though no private keys were compromised and current mainnet programs remain unaffected. Raydium's treasury will compensate affected users while conducting a security review.

The Raydium exploit reveals a critical vulnerability in deprecated smart contract infrastructure—a reminder that legacy code often contains security risks that persist even after upgrades. The attacker exploited an LP mint validation flaw in the Legacy AMM V3, bypassing proportion checks by creating fraudulent LP tokens. This is a sophisticated attack that required understanding the contract's architectural weaknesses rather than brute-force hacking. The isolation to idle, deprecated pools suggests Raydium's migration strategy inadvertently left vulnerable liquidity pools operational.

This incident fits a broader pattern in DeFi where protocol upgrades leave legacy versions active too long, creating security gaps. Many projects maintain backward compatibility or deprecation periods that create lingering attack surfaces. The $1.34M loss, while material, represents a contained incident rather than systemic failure—only five pools were affected, and the mainnet programs remain secure.

For investors and developers, this highlights the importance of rigorous security audits during protocol transitions. The fact that Raydium's treasury will compensate victims demonstrates responsible incident response, but shifts losses from exploiters to token holders. Liquidity providers who used deprecated pools now face recognition that legacy infrastructure carries increased risk.

The incident reinforces that deprecation timelines must balance backward compatibility with security exposure. Raydium's immediate treasury commitment and planned security review are standard practices, but the real test involves preventing similar vulnerabilities in future upgrades and accelerating timelines for sunsetting legacy contracts.

• →A $1.34M exploit leveraged an LP mint validation flaw in Raydium's deprecated Legacy AMM V3 pools, not a key compromise or mainnet vulnerability.
• →Only five idle pools were affected, and current Raydium mainnet programs and SDK remain fully operational and secure.
• →The attacker created fake LP tokens to bypass proportion checks, demonstrating sophisticated contract-level attack knowledge rather than basic security failures.
• →Raydium's treasury will fully compensate victims, but the incident underscores risks associated with maintaining legacy protocol versions.
• →Deprecation periods in DeFi protocols create lingering security surfaces that require faster sunsetting and rigorous audits before major upgrades.