HCE2-SA-2025-0252 Important HCE 2.0 Security Fix(es): A multi-vendor cache poisoning vulnerability named _x27;Rebirthday Attack_x27; has been discovered in caching resolvers that support EDNS Client Subnet (ECS). Unbound is also vulnerable when compiled with ECS support, i.e., _x27;--enable-subnet_x27;, AND configured to send ECS information along with queries to upstream name servers, i.e., at least one of the _x27;send-client-subnet_x27;, _x27;client-subnet-zone_x27; or _x27;client-subnet-always-forward_x27; options is used. Resolvers supporting ECS need to segregate outgoing queries to accommodate for different outgoing ECS information. This re-opens up resolvers to a birthday paradox attack (Rebirthday Attack) that tries to match the DNS transaction ID in order to cache non-ECS poisonous replies. (CVE-2025-5994) HCE 2.0 python3-unbound-1.13.2-3.r11.hce2.aarch64.rpm unbound-1.13.2-3.r11.hce2.aarch64.rpm unbound-devel-1.13.2-3.r11.hce2.aarch64.rpm unbound-help-1.13.2-3.r11.hce2.aarch64.rpm unbound-libs-1.13.2-3.r11.hce2.aarch64.rpm python3-unbound-1.13.2-3.r11.hce2.x86_64.rpm unbound-1.13.2-3.r11.hce2.x86_64.rpm unbound-devel-1.13.2-3.r11.hce2.x86_64.rpm unbound-help-1.13.2-3.r11.hce2.x86_64.rpm unbound-libs-1.13.2-3.r11.hce2.x86_64.rpm