In versions 1.6 to 2.0.11 of Eclipse Mosquitto, an MQTT v5 client connecting with a large number of user-property properties could cause excessive CPU usage, leading to a loss of performance and possible denial of service.
Credits
This issue was discovered and reported by Zhanxiang Song, Bin Yuan, DeQing Zou, Hai Jin, Huazhong Univ. of Sci. & Tech.; Luyi Xing, IU; Yan Jia, Nankai University
