Polygon Fixes Multiple Security Flaws Through Recent Network Hard Forks

Polygon has revealed a set of previously undisclosed security vulnerabilities in its proof of stake network, confirming that fixes were already rolled out through two hard forks before the flaws were made public.

The issues affected Polygon’s Bor and Heimdall client software and included risks such as denial-of-service attacks, excessive validator resource usage, and problems in how checkpoints and milestones were processed. According to a recent disclosure from the project’s validator support team, the flaws were resolved through the Austin and Kyoto hard forks, both of which were tested privately before going live on mainnet.

Heimdall Flaw Was the Most Serious

The riskiest vulnerability involved Heimdall, where a maliciously designed transaction could overload validators with heavy processing demands, threatening network stability. Separately, the Austin fork fixed two denial-of-service weaknesses in Bor that could have slowed transactions or crashed nodes entirely.

No Signs of Exploitation, Upgrades Now Mandatory

Polygon stated there was no evidence that the vulnerabilities were used to attack the live network. However, any nodes still running outdated versions of Bor or Heimdall have already lost sync with the network and must update immediately. Bor v2.10.0 is now required for all Polygon PoS nodes, while Heimdall v0.11.0 is mandatory for validators and full nodes.

Polygon’s native token, POL, was recently trading near $0.10, down slightly over the past week but showing solid monthly gains.