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Defendor

Arsen

Weekly Solana security — exploits, news, research decoded by a real auditor.

Platform
Substack
PricingOnly free issuesPublishesWeekly
Issues19Founded4 months agoLast Issue8 days ago
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Latest Issues

Witnessed, Not Constrained

Hey, it’s Arsen.

In today’s menu:
• How an AI agent found a 4-year-old ZK circuit inflation bug
• Bounty retired, silent patch, then a $10.7M exploit
• One missing height check that split a chain permanently
• And more…


###...

8 days ago
2

Halted By Design

Hey, it’s Arsen.

In today’s menu:
• The public string that gave anyone access to 86 Gnosis Safes
• One failed Sui transaction that halted every honest validator
• The Arbitrum DAO just voted on where frozen KelpDAO ETH goes
• And...

15 days ago

The Deferred Check

Hey, it’s Arsen.

In today’s menu:
• A p-token vulnerability was discovered — batch instruction + deferred ownership = inflated wrapped SOL
• OpenZeppelin goes continuous — what their new model signals for the industry
• Vitalik on fo...

22 days ago
1

The Free Variable

Hey, it’s Arsen.

In today’s menu:
• How a newly churned node reconstructed a vault key and drained $10.7M
• The end of Code4rena
• Four proof fields no one verified — and why that breaks a $60M blockchain
• And more…


🏴‍...

a month ago

The Signer You Trust

Hey, it’s Arsen.

In today’s menu:
• How a phished npm maintainer drained $160K from live Solana dApps
• The fuzzer that surfaced a phantom stake bug in seconds
• AI agents at 70% on exploit construction — still failing at the hard pa...

a month ago

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