Syscoin Pauses Bridge After Exploit Creates 5 Billion Fake SYS

Highlights: 

• Syscoin has halted its bridge system operation after exploits gained unauthorized access and created 5 billion fake SYS.
• The fake tokens were moved between two wallets, with one holding 4 billion tokens and the other 1 billion tokens. 
• The security team said it will continue investigating the incident while it fixes the vulnerability that exposed its bridge system.  

Decentralized Finance (DeFi) platform Syscoin Bridge has confirmed a major hack involving its bridge system. In a X post on Sunday, the platform reported that the attacker managed to create about 5 billion SYS tokens without proper authorization. The incident led Syscoin’s security team to halt operations on its bridge to prevent further exploits. At the same time, the platform is investigating the incident to identify the vulnerabilities that enabled the hacker to gain unauthorized access to its bridge system.  

The Syscoin security team stated:

“The Syscoin bridge is currently paused while the team investigates, finalizes the fix, and works on rectifying the unauthorized SYS output created through the affected bridge path.”

Syscoin reports Bridge incident involving about 5B unauthorized SYS outputs

Syscoin said in a preliminary postmortem that its Bridge has been paused after a security incident involving about 5B SYS.

According to Syscoin, an attacker exploited a validation issue in the Bridge… pic.twitter.com/HgfLAyH1yr

— Wu Blockchain (@WuBlockchain) June 8, 2026

Early Investigation Findings Reveal Cause of the Exploit

Syscoin explained that the vulnerability was from a flaw in its bridge verification process, which wrongly accepted a transaction and allowed fake SYS tokens to be generated on the network’s UTXO side. The platform added that immediately after the unauthorized funds were created, they were quickly moved across several wallet addresses. The first destination wallet received the entire tokens before the funds were later divided into smaller portions. 

Investigators tracking the fake tokens’ movement reported that roughly 4 billion SYS is currently linked to one wallet address, while another wallet holds approximately 1 billion SYS tokens. The team also publicized the transaction records of the addresses connected to the incident. This makes it easy for community members to track the tokens’ on-chain movements. 

Syscoin Pauses Bridge, Highlights Steps to Mitigate Recurrence

Aside from halting its bridge operations, Syscoin said it has contacted exchanges and ecosystem partners. With this, the platform aims to block or closely monitor any deposits linked to the affected wallets. It will also prevent hackers from moving the funds on major platforms.   

In addition, Syscoin stated that developers have already identified the specific part of the bridge system that enabled the exploit, and its team is already preparing to fix it. “Our priority now is to complete implementation and review of the fix, while also determining the correct process to rectify the unauthorized SYS output and neutralize its impact on the network,” Syscoin added.  

The DeFi platform also stated that its bridge system will remain offline until investigations are complete and the team is confident about the system’s integrity. Syscoin also warned users not to interact with the bridge during this period.

Syscoin emphasized that the incident is a top priority and further updates will be provided as investigations progress. Overall, the incident highlights the rising risks in hybrid UTXO-EVM bridge architectures. It also underscores the importance of thorough proof validation in cross-chain systems. 

AI hacks are real although in hindsight this was an obvious one and pretty lame that I didn't catch it was a multiple of things correlating together with a clean re-write of SPT (UTXO assets – Syscoin Platform Tokens) and supporting multi-asset ERC20, ERC721, ERC1155 first-class… https://t.co/Vlfi6LTgLV

— jagdeep sidhu (@realSidhuJag) June 7, 2026

Crypto Losses Drop to Less Than $100M in May After Heavy Exploits in April

On June 1, Crypto2Community reported that crypto losses in May dropped to about $68 million after hitting $650 million in April. According to the publication, May became the third month in which crypto losses remained below $100 million. Code vulnerabilities accounted for the largest share of losses in May. Wallet and private key compromises were the second-largest cause of crypto losses.

These weaknesses led to losses worth approximately $45 million and $13.7 million, respectively. Moreover, roughly $2.6 million of the total losses in May came from phishing attacks. In addition, roughly $9.4 million was returned or recovered during the month.