What’s Vulnerable › Vulnerabilities
CVE-2026-72656: Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-13 · updated 2026-09-04
- Weakness: CWE-789
Description
Memory Allocation with Excessive Size Value (CWE-789) in the ES|QL query processing of Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated user able to submit ES|QL queries could send a specially crafted query whose evaluation allocates an unbounded amount of heap memory, exhausting the available heap on the receiving node and causing the node to become unavailable.
Affected products
- Elasticsearch: from 8.11.0 before 8.18.0 — fixed in 8.18.0
How to fix
Upgrade to a fixed version: Elasticsearch 8.18.0. Check the vendor advisory for mitigations.
References
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