Polygon has fixed security vulnerabilities through two hard forks, which were previously deployed privately

Polygon Labs disclosed that it has fixed a batch of security vulnerabilities in its proof-of-stake network through two hard forks, with the related fixes privately deployed before public disclosure. According to a forum post released on Wednesday, the team packaged the fixes into the Austin hard fork of the Bor client and the Kyoto hard fork of the Heimdall client, both of which followed the standard process for fixing issues that affect consensus: first validated on the Amoy testnet, and then publicly disclosed once the mainnet was activated and the network was secure.

The Austin fork fixed two denial-of-service paths in block processing, including a vulnerability where malicious block producers could crash peer nodes by filling them with oversized field data. The Kyoto fork addressed a broader range of consensus hardening issues, with the most severe vulnerability allowing an attacker to force the entire validator set to perform costly and coordinated work with just one crafted transaction—the cost of constructing the transaction is low, but the network processing cost is high. Polygon emphasized that none of the vulnerabilities were observed to be exploited on the mainnet and have been proactively addressed. The two upgrades are now mandatory for node operators and have taken effect without the need for state migration or resynchronization.

This disclosure comes at a critical transformation period for Polygon, which has completed the migration of the traditional MATIC token to POL as part of a comprehensive overhaul of its network architecture. The news did not boost the price of POL; according to CoinGecko data, POL traded at approximately $0.09983 on Sunday, down 2.3% in 24 hours, down about 6.8% over the past week, and down about 60.8% over the past year, with a market capitalization of approximately $1.07 billion.