Unbound 1.23.1 This security release fixes the Rebirthday Attack CVE-2025-5994. This re-opens up resolvers to a birthday paradox, for EDNS client subnet servers that respond with non-ECS answers. It only affects Unbound when compiled with --enable-subnet, and subnetmod is enabled with config options that send ECS information to upstream servers. The CVE is described here https://nlnetlabs.nl/downloads/unbound/CVE-2025-5994.txt We would like to thank Xiang Li (AOSP Lab, Nankai University) for discovering and responsibly disclosing the vulnerability. Bug Fixes: - Fix RebirthDay Attack CVE-2025-5994, reported by Xiang Li from AOSP Lab Nankai University.