Polygon fixes validator security flaws with Austin and Kyoto forks

Polygon Labs has patched several security flaws across its proof-of-stake network through two coordinated hard forks, including a vulnerability that could have forced the full validator set to perform costly processing from a single crafted transaction. Summary Polygon patched several PoS security vulnerabilities through the Austin and Kyoto hard forks before publicly disclosing the fixes. 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. Polygon’s Validators Support Team disclosed the fixes in an Aug. 27 forum post after the Austin and Kyoto hard forks had already been tested and activated. The team said consensus-affecting security fixes were deployed privately, validated on the Amoy testnet and disclosed only after the mainnet fleet was protected. The vulnerabilities affected Bor, Polygon PoS’s execution client, and Heimdall, which handles validator ...