[Release] Checkmk stable release 2.4.0p26

Dear friends of Checkmk,

the new stable release 2.4.0p26 of Checkmk is ready for download.

This stable release ships with 79 changes affecting all editions of Checkmk,
5 changes for all commercial editions, 4 Ultimate specific and
1 Ultimate with multi-tenancy specific changes.

Support periods can be found here: Checkmk versions

Changes in all Checkmk editions:

Agent Bakery

  • 19194 FIX: Windows MySQL plugin: fix mysql.exe binary detection for non-default installations…

BI

  • 19676 FIX: Add grouping to single aggregation and availability views…

Checks & agents

  • 19552 Redfish: add PDU, power consumption, and power redundancy monitoring…
  • 19192 Windows agent: disable WinDbg logging by default…
  • 19562 Added New RA3S SNMP Check Plugins…
  • 19179 aws_ec2_limits: Added Graphs for Several AWS EC2 Instance Types…
  • 18895 FIX: Fix temperature thresholds of Aruba 6100+ switches…
    NOTE: Please refer to the migration notes!
  • 19564 FIX: Fixed Macro Processing for HTTP Headers in HTTPv2 Check Plugin…
    NOTE: Please refer to the migration notes!
  • 16913 FIX: Generic Printer: Default output tray levels interpreted as ‘filled’ rather than ‘remaining’…
    NOTE: Please refer to the migration notes!
  • 19297 FIX: NetApp ONTAP special agent: section failures no longer abort all monitoring…
    NOTE: Please refer to the migration notes!
  • 19445 FIX: kube_node_count: Fix control-plane node detection with default role name…
    NOTE: Please refer to the migration notes!
  • 18971 FIX: netapp_ontap_{volumes,snapshots}: Allow continued use of old netapp_api_{volumes,snapshots} service name…
    NOTE: Please refer to the migration notes!
  • 19457 FIX: Docker container disk IO: service goes UNKNOWN when all counters are zero…
  • 19357 FIX: Fix CPU load discovery for Skyhigh Secure Web Gateway…
  • 18586 FIX: Fix DRBD agent to collect all volumes, not just volume 0…
  • 19720 FIX: Fix DRBD stats parsing for 9.x bracket notation…
  • 19068 FIX: Fix Dell Compellent disk health state: not healthy reported as UNKNOWN…
  • 19528 FIX: Fix HyperV Checkpoints crash on negative checkpoint age…
  • 18554 FIX: Fix Oracle SQL check displaying long output in service summary…
  • 19428 FIX: Fix POP3-based email active checks crashing with AssertionError…
  • 19556 FIX: Fix Redfish agent error on BMCs that omit Systems from service root…
  • 19101 FIX: Fix aruba_sw_temp to skip absent temperature sensors…
  • 19170 FIX: Fix checkpoint_svn_status check crashing when code is missing…
  • 19472 FIX: Fix false CRIT for NetApp temperature sensors without transceivers…
  • 19296 FIX: Fix graph unit display for Snapshots Volume service…
  • 19565 FIX: Improved Interface Metric Processing When Multiple Up-time Values Are Present…
  • 19444 FIX: Kubernetes: handle missing creationTimestamp gracefully…
  • 19470 FIX: NetApp ONTAP: fix crash for interfaces with no broadcast domain…
  • 19184 FIX: Only parse required keys for Bazel plugins…
  • 19417 FIX: Piggyback Hub: Fix crash when many piggyback hosts are updated at once…
  • 18742 FIX: Tripp Lite UPS: Fix detection for devices with extended sysObjectID…
  • 19193 FIX: Windows agent now opens firewall port before starting the agent controller…
  • 16910 FIX: agent_hp_msa: session build up due to unsuccessful logout attempts…
  • 19281 FIX: cisco_fantray: Fix discovery failure when entPhysicalName is empty…
  • 19498 FIX: cisco_temperature: Sensors with empty description are no longer skipped…
  • 18975 FIX: ibm_mq_queues: Support additional QStatus informations from CSQM format…
  • 18488 FIX: mk_oracle: fix unwanted output in oracle_asm_diskgroup section…

Core & setup

  • 19415 FIX: Fix piggybacked host not handled correctly when source identifies it by IP address…

Linux distributions

  • 19572 FIX: Fix installation on SLES 16.0: add missing libexslt0 dependency…

Livestatus

  • 18956 FIX: Fix crash if remote site is not alive…
  • 19585 FIX: Fixed various edge cases of the availability calculation…

Notifications

  • 19425 Add button to just save notification on edit…
  • 17989 SEC: Potential livestatus injection in notification test mode…
  • 19089 FIX: Improve notification rule rendering…
  • 19099 FIX: Improve notification statistics livestatus query performance…
  • 19424 FIX: Preserve search query consistently across notification rule actions…
  • 19092 FIX: Test notifications: Respect host tags…

Other components

  • 19529 FIX: NagVis: Updated to 1.9.49…

REST API

  • 18582 FIX: Fix negation in REST API Livestatus queries…
  • 19493 FIX: downtimes: deleting downtimes by hostgroup should match on the exact hostgroup…

Setup

  • 19605 Add opt-in product usage analytics…
  • 18955 Rotate Cookie signature secret on updates…
  • 19056 Support Diagnostics: Improve sensitivity handling…
  • 19059 Support Diagnostics: Redact passwords in configuration files…
  • 19364 FIX: Fix wrong inline help shown on host tag dropdowns…
  • 19411 FIX: “Use new service names” global setting now uses titled sections per plugin…
  • 19043 FIX: Crash when displaying rules with wildcard host name conditions…
  • 19494 FIX: Fix audit log showing wrong role name after cloning a user role…
  • 18987 FIX: Fix crash in global rule search when rule contains invalid regex…
  • 19522 FIX: Fix crash when viewing parameters for services of third-party check plugins…
  • 19359 FIX: Fix drag-and-drop reordering in sortable tables…
  • 19097 FIX: Fix slow “Total Sent Notifications” link due to missing time filter…
  • 19527 FIX: Fix topology data files deleted on remote sites during activation…
  • 18375 FIX: Increased timeout duration for activate changes…
  • 19477 FIX: LDAP: User Synchronize for Active Directory can unlock users…
  • 18988 FIX: Rulesets: Validate regex pattern in explicit host conditions…

Site management

  • 19700 FIX: Enable site restore in Checkmk Docker containers…
  • 19469 FIX: Fix cmk-monitor-broker hanging CheckMk agent runs due to proxy misconfiguration…
  • 18901 FIX: Reenable rrdcached daemon pausing during online backups…
  • 18897 FIX: omd cleanup: Don’t try to purge dpkg-query…
  • 18898 FIX: omd config: Fix KeyError: ‘Add-ons’…

User interface

  • 17990 SEC: Potential livestatus injection in prediction graph page…
  • 19517 FIX: Fix service state filter not shown in filter sidebar…
    NOTE: Please refer to the migration notes!
  • 18996 FIX: Fix ‘find on this page’…
  • 19519 FIX: Fix empty host/service group columns in CSV and JSON export…
  • 19555 FIX: Fix missing “Inventory history of host” menu entry when site parameter is lost…
  • 19094 FIX: Fix random title order in Service Detail View…
  • 19299 FIX: Restrict RabbitMQ inter-site broker to TLS 1.3 only…
  • 19320 FIX: Views: Fix grouping by HW/SW inventory attributes…

Changes in Checkmk commercial editions:

Checks & agents

  • 19447 FIX: Kubernetes (OpenShift): Fix absence of Prometheus metrics data coming from newer Thanos versions…

REST API

  • 19499 FIX: LDAP: api groups_to_roles now supports custom user roles…

Reporting & availability

  • 19093 FIX: Sub reports: Inherit time range from parent report…
    NOTE: Please refer to the migration notes!
  • 19098 FIX: Fix empty error message when scheduled report email delivery fails…

Setup, site management

  • 19497 FIX: SAML: Users with no matching role mapping now receive default roles instead of empty roles…

Changes in Checkmk Ultimate:

Checks & agents

  • 19412 OTel: Monitor data flow of collector…
  • 19127 FIX: OTel metrics: rate computation no longer applies to histogram types…
    NOTE: Please refer to the migration notes!
  • 18743 FIX: OTel: Disabled collector configurations are still applied…

Metrics system

  • 19126 FIX: Fix OTel Sum metric rate computation for delta temporality…
    NOTE: Please refer to the migration notes!

Changes in Checkmk Cloud:

NO CHANGES

Changes in Checkmk Ultimate with multi-tenancy:

Setup

  • 19095 FIX: Fix internal error when opening GUI design customization…

You can download Checkmk from our download page: https://checkmk.com/download

List of all changes: https://checkmk.com/werks?product=cmk&version=2.4.0p26

We greatly thank you for using Checkmk and wish you a successful monitoring,

Your Checkmk Team

1 Like

Am I correct in assuming that you haven’t yet updated the Python/CPython version deployed with the Windows Agent to the latest release, 3.13.13 , which was released on April 7, 2026, and addresses CVE-2025-15467?

tried to install on debian 13 “apt install ./check-mk-raw-2.4.0p26_0.trixi_amd64.deb” and getting “Unsupported file … given”

Maybe? apt install ./check-mk-raw-2.4.0p26_0.trixie_amd64.deb

1 Like