This new patch release fixes two potential DoS vulnerabilities against florestad. The first one was discovered and reported by Bruno Garcia, and involves sending several low-pow headers as invs after IBD. This would cause the node to eventually reach a OOM condition due to how we track which peers sent us block announcements faster.
The second one was found by Davidson Souza, and is also related to low-pow headers, but this time it could get our reorg code stuck due to slow chain work computation.
Full Changelog: v0.9.0...v0.9.1