What is CVE-2026-26931?

CVE-2026-26931 is a medium-severity vulnerability in Elastic Metricbeat, classified under CWE-789. CVSS score: 5.7/10. Published 2026-03-19.

How severe is CVE-2026-26931?

Medium severity. CVSS v3 base score is 5.7 out of 10.

Vulnerability in Elastic Metricbeat

CVE-2026-26931

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).

Published 2026-03-19 · last modified 2026-09-04.

CVSS v3 metric

CVSS v3 base score 5.7 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (19.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Elastic Metricbeat — versions 8.0.0

Weakness classification (CWE)

CWE-789

References

discuss.elastic.co/t/metricbeat-8-19-13-9-2-5-security-update-esa-2026-09/385532 (Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-26931?: CVE-2026-26931 is a medium-severity vulnerability in Elastic Metricbeat, classified under CWE-789. CVSS score: 5.7/10. Published 2026-03-19.
How severe is CVE-2026-26931?: Medium severity. CVSS v3 base score is 5.7 out of 10.