Balancer Vault rounding-down precision loss actively exploited security flaw
Vulnerability
Summary
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Balancer Vault has a rounding-down precision loss that attackers exploited through batchSwap, creating price manipulation risk in Balancer calculations. The flaw was tied to the Balancer V2 Composable Stable Pools attack and helped drive losses that exceeded $120m.
Related Happenings
Balancer Protocol hit by cyberattack
Incident
First: 03.11.2025 23:53
Last: 03.11.2025 23:53
Sources 1
How related:
However, yesterday morning UK time, the firm experienced an attack targeting its Balancer V2 Composable Stable Pools.
About this happening:
**Balancer Protocol** confirmed a **protocol exploit** in its **V2 Compostable Stable Pools**, with losses reportedly exceeding **$128 million**. The incident was confirmed at **7...
Balancer Protocol hit by cyberattack
IncidentHow related: However, yesterday morning UK time, the firm experienced an attack targeting its Balancer V2 Composable Stable Pools.
About this happening: **Balancer Protocol** confirmed a **protocol exploit** in its **V2 Compostable Stable Pools**, with losses reportedly exceeding **$128 million**. The incident was confirmed at **7...
Timeline
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04.11.2025 11:45 2 articles · 6mo ago
Balancer V2 Composable Stable Pools attack exploits rounding-down precision loss
Exploitation ObservedBalancer reported that its Balancer V2 Composable Stable Pools were attacked yesterday morning UK time, and security researchers said the raid exploited a rounding down precision loss in Balancer Vault calculations. The batchSwap function was said to amplify the flaw by enabling crafted parameters to manipulate token prices, with losses estimated to exceed $120m.
Show sources
- DeFi Protocol Balancer Loses Over $120m in Cyber Heist — www.infosecurity-magazine.com — 04.11.2025 11:45
- DeFi Protocol Balancer Loses Over $120m in Cyber Heist — www.infosecurity-magazine.com — 04.11.2025 11:45