Polygon Fixes Validator Security Flaws with Austin and Kyoto Forks

Polygon has patched several security flaws across its proof-of-stake network through two coordinated hard forks, Austin and Kyoto. The vulnerabilities affected Bor, Polygon's execution client, and Heimdall, which handles validator coordination and other consensus functions.

The Austin fork closed two denial of service paths, including one that could let a malicious block producer crash peer nodes. The Kyoto fork fixed a flaw that could force Polygon's validator set to perform costly processing from a single crafted transaction.

Polygon said none of the vulnerabilities were exploited on mainnet, while both upgrades are now mandatory for node operators. Older Polygon nodes have fallen out of consensus and must be updated to rejoin the network.