Tools Crypto Exploit Tracker exploit-0035
Exploit record
Syscoin Bridge
- Loss
- $10M
- Attack vector
- Bridge Exploit
- Chain
- Syscoin
- Sector
- Bridge
What happened
In early June 2026 an attacker exploited a proof-parsing flaw in the Syscoin bridge relay to mint roughly 5 billion unauthorised SYS tokens, an incident valued at about $10 million; SYS fell around 20%.
The bridge relay's proof-validation code misparsed a deliberately malformed proof, treating it as valid evidence of a burn on the NEVM side that never happened, which authorised minting on the UTXO side. Syscoin halted the bridge, coordinated freezes with exchanges and partners, and later said it had recovered and burnt all 5 billion minted SYS, restoring the pre-exploit supply, though the bridge remained offline.
Sources
One record from the Crypto Exploit Tracker, maintained by the Security Desk. Data: CSV · JSON ·RSS · CC BY 4.0 with attribution to YFarmX.Tracker updated · 15 September 2026