⚠️ Security: Improves sender side handling of RETIRE_CONNECTION_ID frames. Without this an attacker could trigger an infinite loop by sending a specially-crafted set of frames that trigger a connection ID retirement (CVE-2025-7054). Highlights: Added Config::set_initial_rtt() to allow control of a connection's initial RTT estimate. Improvements and bug fixes to datagram packetization layer path MTU discovery (DPLPMTUD). Other bug fixes and performance improvements.
