Elastic Cloud incident

Replication bug causing slow recoveries

Major Resolved View vendor source →

Elastic Cloud experienced a major incident on September 1, 2026 affecting Elastic Cloud Hosted, lasting 29d 12h. The incident has been resolved; the full update timeline is below.

Started
Sep 01, 2026, 08:16 AM UTC
Resolved
Sep 30, 2026, 08:44 PM UTC
Duration
29d 12h
Detected by Pingoru
Sep 01, 2026, 08:16 AM UTC

Affected components

Elastic Cloud Hosted

Update timeline

  1. investigating Sep 01, 2026, 08:16 AM UTC

    We are aware of a bug affecting customers on Elasticsearch versions 9.5.0, 9.5.1 and 9.5.2 where bulk index operations processed on the primary shard can result in divergence on the replicas resulting in high disk usage and long-running recoveries. The team is working on a fix. More information can be found on https://www.elastic.co/docs/release-notes/elasticsearch/known-issues#elasticsearch-9.5.2-known-issues The next update will be in the next 2 hours or sooner if needed.

  2. identified Sep 01, 2026, 11:07 AM UTC

    We have identified the root cause and the team is working on a fix scheduled to be released in Elasticsearch version 9.5.3 What you can do: - If you have not yet upgraded to 9.5.*, you are not affected as upgrades to 9.5 have been disabled until 9.5.3 is released - If you are already running 9.5 and experience the symptoms of this issue, please contact Elastic Support. More information can be found on https://www.elastic.co/docs/release-notes/elasticsearch/known-issues#elasticsearch-9.5.2-known-issues

  3. identified Sep 01, 2026, 03:46 PM UTC

    The fix has been identified and backported to the Elasticsearch 9.5 patch branch. The teams are performing the needed validations before scheduling and rolling out the 9.5.3 release.

  4. monitoring Sep 03, 2026, 12:13 PM UTC

    Elasticsearch 9.5.3 has been released and all Elastic Cloud and On-Premises customers currently running 9.5.0, 9.5.1 or 9.5.2 are advised to update to this new version as soon as possible.

  5. monitoring Sep 03, 2026, 03:47 PM UTC

    Elasticsearch 9.5.3 has been released and all customers currently running 9.5.0, 9.5.1 or 9.5.2 are advised to update to this new version as soon as possible. Impacted customers are advised to follow the workaround steps from https://github.com/elastic/elasticsearch/issues/158212 after the upgrade.

  6. resolved Sep 30, 2026, 08:44 PM UTC

    This issue was resolved in the 9.5.3 release of Elasticsearch. Customers running versions 9.5.0, 9.5.1, or 9.5.2 of Elasticsearch are advised to update to a newer version as soon as possible.