Metricbeat 8.19.13, 9.2.5 Security Update (ESA-2026-09)

Announcements Security Announcements
1

Memory Allocation with Excessive Size Value in Metricbeat Leading to Denial of Service

Memory Allocation with Excessive Size Value (CWE-789) in the Prometheus remote_write HTTP handler in Metricbeat can lead Denial of Service via Excessive Allocation (CAPEC-130).

Affected Versions:

  • 8.x: All versions from 8.0.0 up to and including 8.19.12
  • 9.x: All versions from 9.0.0 up to and including 9.2.4

Affected Configurations:
The Prometheus remote_write module is not enabled by default in Metricbeat, so this issue only affects users who have enabled it.

Solutions and Mitigations:

The issue is resolved in version 8.19.13, 9.2.5 .

For Users that Cannot Upgrade:

  1. Disable the remote_write module if it is not required for operations:
    • Remove or comment out the Prometheus remote_write configuration block in metricbeat.yml
    • Restart Metricbeat to apply changes
  2. Restrict network access using firewall rules or network policies:
    • Limit access to the remote_write endpoint to trusted Prometheus server IP addresses only
    • Use host: "localhost" binding if the Prometheus server runs on the same host

Indicators of Compromise (IOC)

Log Patterns:

  • Metricbeat process termination with “out of memory" messages in system logs
  • Repeated Metricbeat crashes or restarts when the Prometheus remote_write module is enabled
  • OOM events in kernel logs dmesg or container orchestration logs targeting the Metricbeat process

Audit Trail Indicators:

  • Sudden memory consumption spikes in Metricbeat process metrics immediately preceding process termination
  • Network connections from unexpected or unauthorized source IP addresses to the remote_write endpoint port

Severity: CVSSv3.1: Medium ( 5.7 ) - CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVE ID: CVE-2026-26931
Problem Type: CWE-789 - Memory Allocation with Excessive Size Value
Impact: CAPEC-130 - Excessive Allocation