Polygon disclosed several previously private security vulnerabilities in its Bor and Heimdall proof‑of‑stake clients that could have disrupted the network, and said the issues were fixed through the Austin and Kyoto hard forks. The vulnerabilities included denial‑of‑service risks, validator resource exhaustion and flaws affecting checkpoint and milestone processing, according to a Thursday disclosure from Polygon Labs’ Validators Support Team. The most severe issue involved Heimdall, where a specially crafted transaction could force validators to perform excessive processing work, potentially disrupting the network. Austin addressed two denial‑of‑service risks in Bor that could slow block processing or cause nodes to crash. Polygon reported no observed exploitation on the mainnet and said the fixes were deployed proactively before the details were made public. Nodes running older client versions past the hard fork activation heights must upgrade to rejoin the canonical network; Bor v2.10.0 is required for all Polygon PoS nodes and Heimdall v0.11.0 is required for validators and full nodes, both upgrades already active on mainnet. POL, Polygon’s native token, was trading around $0.10 at the time of writing, down about 4% over the past week but up 44% over the past month and 2.3% year to date, according to CoinGecko data. The network continues to operate with the updated clients while monitoring for any further issues.