Fleet and Elastic Agent 8.18.0

Details

In late 8.x releases, there’s a bug in the Fleet UI that causes 9.0.0 to appear as an option for Elastic Agent upgrades. This option results in an error when selected, as upgrades across major releases are not supported for Elastic Agent. For example, an agent can’t be upgraded to version 9.0 while Kibana and Fleet Server are on version 8.x.

The Elastic Agent upgrade is not selectable:

The Fleet Server upgrade is selectable, with an inconsistent UI state and error on submit:

Impact

In the 9.x releases, the option that appears in the UI for an upgrade across a major release should be ignored.

Details
There is a known issue where an Elastic Agent installed on Windows and previously enrolled into Fleet is unable to re-enroll. Attempting to enroll the Elastic Agent fails with the following error:

Error: the command is executed as root but the program files are not owned by the root user.

Impact
The issue affects Elastic Agent installed on Windows. Until a bug fix is available in a later release, you can temporarily resolve the issue by changing the ownership of the Elastic Agent directory:

icacls "C:\Program Files\Elastic\Agent" /setowner "NT AUTHORITY\SYSTEM" /t /l

After the output confirms all files were successfully processed, run the enroll command again.

Details

There is a known issue where Elastic Agent remains in an Upgrade scheduled state when a scheduled Elastic Agent upgrade is cancelled. Attempting to restart the upgrade on the UI returns an error: The selected agent is not upgradeable: agent is already being upgraded..

Impact

Until this issue is fixed in a later patch version, you can call the Upgrade an agent endpoint of the Kibana Fleet API with the force parameter set to true to force-upgrade the Elastic Agent:

curl --request POST \
  --url https://<KIBANA_HOST>/api/fleet/agents/<AGENT_ID>/upgrade \
  --user "<SUPERUSER_NAME>:<SUPERUSER_PASSWORD>" \
  --header 'Content-Type: application/json' \
  --header 'kbn-xsrf: true' \
  --data '{"version": "<VERSION>","force": true}'

To force-upgrade multiple Elastic Agents, call the Bulk upgrade agents endpoint of the Kibana Fleet API with the force parameter set to true:

curl --request POST \
  --url https://<KIBANA_HOST>/api/fleet/agents/bulk_upgrade \
  --user "<SUPERUSER_NAME>:<SUPERUSER_PASSWORD>" \
  --header 'Content-Type: application/json' \
  --header 'kbn-xsrf: true' \
  --data '{"version": "<VERSION>","force": true,"agents":["<AGENT_IDS>"]}'

Details

On May 2, 2025 a known issue was discovered that the .fleet-agents index template was missing a mapping for the local_metadata.complete attribute. This may cause agent checkins to be rejected and the agents to appear as offline.

In this Fleet’s logs this will appear as:

elastic fail 400: document_parsing_exception: [1:209] object mapping for [local_metadata] tried to parse field [local_metadata] as object, but found a concrete value
Eat bulk checkin error; Keep on truckin'

And in the Elastic Agent logs it will appear as:

"log.level":"error","@timestamp":"2025-04-22:12:35:25.295Z","message":"Eat bulk checkin error; Keep on truckin'","component":{"binary":"fleet-server","dataset":"elastic_agent.fleet_server","id":"fleet-server-es-containerhost","type":"fleet-server"},"log":{"source":"fleet-server-es-containerhost"},"service.type":"fleet-server","error.message":"elastic fail 400: document_parsing_exception: [1:209] object mapping for [local_metadata] tried to parse field [local_metadata] as object, but found a concrete value","ecs.version":"1.6.0","service.name":"fleet-server","ecs.version":"1.6.0"

This attribute was added to the template in versions: 8.17.11 8.18.3, and 8.19.3.

Further investigation revealed that the .fleet-agents index template was not correctly applied due to an unchanged _meta.managed_index_mappings_version number. This change also affects other attributes as well, such as upgrade_attempts, namespaces, unprivileged, and unhealthy_reason. If there is an error related to any of these attributes, there will be a similar error message in the logs.

Impact

Updating to a version with a fixed _meta.managed_index_mappings_version will correctly apply the new index template. The fixed versions are 8.18.8, 8.19.4, 9.0.8, 9.1.4.