Release Notes for Zabbix 1.8.21rc1

Zabbix Team is pleased to announce the availability of Zabbix 1.8.21rc1.

Zabbix is an enterprise-class open source distributed monitoring solution. Zabbix is released under the GPL, thus it is free of charge for both commercial and non-commercial use. A complete text of the license is available at

This document contains the release notes for Zabbix 1.8.21rc1. Download it from downloads.

The following sections describe the release in details and provide late-breaking or other information that supplements its main documentation.

Fixes and minor improvements

ZBX-3407 fixed NVPS query to not fail on DB2
ZBX-8608 added support of IP masks for action conditions
ZBX-8151 fixed XXE vulnerability on XML import using obsolete libxml versions; thanks to [email protected] for the report
ZBX-8343 fixed a bug in binary heap that could cause a slightly inconsistent ordering of elements in the queue
ZBX-8198 decreased verbosity of Windows agent with DebugLevel=4
ZBX-7930 improved SQL performance and execution time in Maintenance page

Installation and Upgrade Notes


See Zabbix Manual for full details.


Recompile Zabbix binaries and update front-end PHP files. Execute a database patch if migrating from Zabbix 1.8.x. See Zabbix Manual for a detailed upgrade procedure.

Commercial support

Zabbix Company provides a full range of Professional Services. We also provide trouble-free Upgrade Service for easy migration from earlier versions of Zabbix. Please contact Sales for pricing and more details.


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