Mosquitto 1.6.11 has been released, this is a bugfix release.


  • On Windows the Mosquitto service was being installed without appropriate path quoting, this has been fixed. Closes #565671.


  • Fix usage message only mentioning v3.1.1. Closes #1713.
  • Fix broker refusing to start if only websockets listeners were defined. Closes #1740.
  • Change systemd unit files to create /var/log/mosquitto before starting. Closes #821.
  • Don't quit with an error if opening the log file isn't possible. Closes #821.
  • Fix bridge topic remapping when using "" as the topic. Closes #1749.
  • Fix messages being queued for disconnected bridges when clean start was set to true. Closes #1729.
  • Fix autosave_interval not being triggered by messages being delivered. Closes #1726.
  • Fix websockets clients sometimes not being disconnected promptly. Closes #1718.
  • Fix "slow" file based logging by switching to line based buffering. Closes #1689. Closes #1741.
  • Log protocol error message where appropriate from a bad UNSUBSCRIBE, rather than the generic "socket error".
  • Don't try to start DLT logging if DLT unavailable, to avoid a long delay when shutting down the broker. Closes #1735.
  • Fix potential memory leaks. Closes #1773. Closes #1774.
  • Fix clients not receiving messages after a previous client with the same client ID and positive will delay interval quit. Closes #1752.
  • Fix overly broad HAVE_PTHREAD_CANCEL compile guard. Closes #1547.

Client library

  • Improved documentation around connect callback return codes. Close #1730.
  • Fix mosquitto_publish*() no longer returning MOSQ_ERR_NO_CONN when not connected. Closes #1725.
  • mosquitto_loop_start() now sets a thread name on Linux, FreeBSD, NetBSD, and OpenBSD. Closes #1777.
  • Fix mosquitto_loop_stop() not stopping on Windows. Closes #1748. Closes #117.