CVE-2025-9624: OpenSearch 3.2.0 - Nested Boolean/Disjunction asymmetric DoS

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-11-25 · updated 2026-10-18
Weakness: CWE-674

Description

A vulnerability in OpenSearch allows attackers to cause Denial of Service (DoS) by submitting complex query_string inputs. This issue affects all OpenSearch versions between 3.0.0 and < 3.3.0 and OpenSearch < 2.19.4.

Affected products

AWS Opensearch: before 3.3.0 — fixed in 3.3.0

How to fix

Upgrade to a fixed version: AWS Opensearch 3.3.0. Check the vendor advisory for mitigations.

References

https://fluidattacks.com/advisories/chick
https://github.com/opensearch-project/OpenSearch/releases/tag/2.19.4
https://github.com/opensearch-project/OpenSearch/releases/tag/3.3.0

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