Polygon Fixes Security Flaws Via Austin and Kyoto Hard Forks

Polygon has addressed multiple previously undisclosed security vulnerabilities in its proof-of-stake (PoS) infrastructure, including issues with node-to-node denial-of-service risk and validator processing bottlenecks.

The problems were fixed via two recent hard forks and corresponding client upgrades: Austin for the Bor client and Kyoto for the Heimdall client. Polygon said none of the vulnerabilities have been observed exploited on mainnet.

The disclosure highlights a more severe problem affecting the Heimdall client, where a specially crafted transaction could force validators to perform excessive processing work. The issue was addressed through the Kyoto hard fork, with corresponding updates rolled out before the information was disclosed publicly.