This is a bugfix release.


  • Fix detection of incoming v3.1/v3.1.1 bridges. Closes #1263.
  • Fix default max_topic_alias listener config not being copied to the in-use listener when compiled without TLS support.
  • Fix random number generation if compiling using WITH_TLS=no and on Linux with glibc >= 2.25. Without this fix, no random numbers would be generated for e.g. on broker client id generation, and so clients connecting expecting this feature would be unable to connect.
  • Fix compilation problem related to getrandom() on non-glibc systems.
  • Fix Will message for a persistent client incorrectly being sent when the client reconnects after a clean disconnect. Closes #1273.
  • Fix Will message for a persistent client not being sent on disconnect. Closes #1273.
  • Improve documentation around the upgrading of persistence files. Closes #1276.
  • Add 'extern "C"' on mosquitto_broker.h and mosquitto_plugin.h for C++ plugin writing. Closes #1290.
  • Fix persistent Websockets clients not receiving messages after they reconnect, having sent DISCONNECT on a previous session. Closes #1227.
  • Disable TLS renegotiation. Client initiated renegotiation is considered to be a potential attack vector against servers. Closes #1257.
  • Fix incorrect shared subscription topic '$shared'.
  • Fix zero length client ids being rejected for MQTT v5 clients with clean start set to true.
  • Fix MQTT v5 overlapping subscription behaviour. Clients now receive message from all matching subscriptions rather than the first one encountered, which ensures the maximum QoS requirement is met.
  • Fix incoming/outgoing quota problems for QoS>0.
  • Remove obsolete store_clean_interval from documentation.

Client library

  • Fix typo causing build error on Windows when building without TLS support. Closes #1264.


  • Fix -L url parsing when /topic part is missing.
  • Stop some error messages being printed even when --quiet was used. Closes #1284.
  • Fix mosquitto_pub exiting with error code 0 when an error occurred. Closes #1285.
  • Fix mosquitto_pub not using the -c option. Closes #1273.
  • Fix MQTT v5 clients not being able to specify a password without a username. Closes #1274.
  • Fix mosquitto_pub -l not handling network failures. Closes #1152.
  • Fix mosquitto_pub -l not handling zero length input. Closes #1302.
  • Fix double free on exit in mosquitto_pub. Closes #1280.


  • Remove references to Python binding and C++ wrapper in libmosquitto man page. Closes #1266.


  • CLIENT_LDFLAGS now uses LDFLAGS. Closes #1294.