Allbridge Core has paused operations following an exploit on Solana that drained roughly $1.66 million from the protocol’s liquidity swimming pools in a single transaction at round 17:51 UTC on July 19, in line with a brand new announcement from the challenge.
The incident is notable not solely due to the scale of the loss, but in addition as a result of Allbridge Core handles important utilization, with over 890,000 wallets and a TVL of over $24 million in line with figures on its homepage. This incident additionally reopens questions concerning the security of liquidity pool-based bridge fashions.
Allbridge Core pauses after Solana exploit
Instantly upon detecting the incident, Allbridge paused Core whereas investigating, noting that it took the workforce about 25 minutes to determine and start shutting down the affected capabilities. The incident occurred on Solana and was confirmed by the challenge in a newly launched technical autopsy.
Allbridge Core is experiencing a safety incident. We’ve got paused the protocol as a precaution whereas we examine.
When you have liquidity in affected swimming pools, please withdraw now.
The ensuing pool imbalance created a short lived constructive arbitrage window. In the event you took benefit… pic.twitter.com/Ovg7yT35SM
— Allbridge (@Allbridge_io) July 19, 2026
Allbridge said that the injury was contained to the 2 related swimming pools, whereas personal keys and person wallets weren’t compromised. Within the preliminary part of dealing with the problem, the challenge shifted its focus to limiting the unfold relatively than permitting the protocol to proceed working usually whereas the pool state was distorted.
Pool-based swap design uncovered a weak point
In keeping with Allbridge’s technical documentation, Core makes use of a stablecoin liquidity pool mannequin with a digital steadiness to keep up inner valuation pegs. This design permits the bridge to function with out wrapped belongings, however it additionally leaves the system closely depending on how the pool handles the discrepancy between precise and recorded balances.
In keeping with the challenge, the vulnerability emerged when same-asset swaps had been executed consecutively in the identical pool. Every subsequent swap pushed the interior state additional away from the precise liquidity, and when a flash mortgage was used as leverage, this deviation was giant sufficient for the attacker to extract worth earlier than the rebalancing mechanism might react.
This incident exhibits that the problem lies within the pool-based swap logic when exploited in a concentrated sequence of transactions, relatively than in Solana as an impartial infrastructure.
About $1.66 million was drained from liquidity swimming pools
In keeping with the autopsy, the exploit occurred at round 17:51 UTC on July 19, and the full worth drained from liquidity swimming pools was roughly $1.66 million, together with about 1,118,239 USDC and 538,692 USDT. Based mostly on the challenge’s description, the attacker initiated the assault with a flash mortgage of round 1.12 million USDC from Kamino, then executed a sequence of swaps to distort the pool ratio earlier than withdrawing liquidity on the skewed value.
9-step exploit circulation. Supply: Allbridge
The cash circulation didn’t cease on Solana after that. In keeping with Allbridge and forensic companions, they traced roughly $1.63 million, with a portion bridged to Ethereum after which passing via channels similar to Railgun, NEAR Intents, and Zcash Orchard. Dispersing via a number of layers like this makes the monitoring and restoration course of considerably extra complicated.
Allbridge strikes to comprise the injury
Allbridge prioritized locking the affected elements earlier than reopening routes that don’t depend on liquidity swimming pools. In keeping with the autopsy, the bridge has now resumed on these routes, whereas pool-based swaps stay disabled as a security measure. The challenge can also be protecting the liquidity pool web page open so LPs can withdraw their funds, whereas recommending they withdraw liquidity early because the swimming pools not generate yields as earlier than.
Allbridge said that person liquidity outdoors the affected swimming pools shouldn’t be immediately threatened. The challenge additionally subsequently referred to as on anybody who took benefit of the momentary value discrepancy after the incident to think about returning these income to assist compensate affected LPs.
The incident quickens a shift to a brand new structure
Allbridge said that Core and Allbridge Basic will stop working of their present kind inside three months, whereas the brand new model of Core will utterly take away liquidity swimming pools and change to routing by way of CCTP and LayerZero to cut back pool imbalance dangers. This can be a step in the precise route for Allbridge Subsequent, the place the challenge goals to prioritize appropriate routing as an alternative of concentrating all transaction flows into the identical mechanism.
With the present utilization scale of Allbridge Core, this alteration exhibits that the exploit goes past a mere technical incident. It’s driving the challenge towards a unique structure whereas demonstrating that the pool-based bridge mannequin has develop into some extent that wants substitute relatively than simply restore.
