What’s Vulnerable › Vulnerabilities
CVE-2026-72687: 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 2026-09-01
- Weakness: CWE-789
Description
A flaw in Elasticsearch allows a low-privileged authenticated user to submit a single small request containing a forged opaque identifier. Elasticsearch decodes and deserializes the identifier before confirming that it was legitimately issued by the cluster, and a size value carried inside the identifier drives an allocation that is neither capped nor accounted for by the available memory-usage controls. The resulting out-of-memory condition is fatal and terminates the affected node process, resulting in a denial of service.
Affected products
- Elasticsearch: from 8.0.0 before 8.19.20; from 9.0.0 before 9.4.5; from 9.5.0 before 9.5.1 — fixed in 8.19.20, 9.4.5, 9.5.1
How to fix
Upgrade to a fixed version: Elasticsearch 8.19.20, 9.4.5, 9.5.1. Check the vendor advisory for mitigations.
References
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