CVE-2026-18428 - OpenSearch SQL Plugin - Async Query Validation Bypass
CVE-2026-18428 is a vulnerability in the OpenSearch SQL plugin that allows users with asynchronous query access to bypass SQL grammar restrictions via the direct query endpoint. This affects both the open-source self-managed OpenSearch SQL plugin versions 2.13 through 3.6 and the AWS managed Amazon OpenSearch Service versions 2.13 through 3.5. The issue arises from insufficient validation in the Flint extension query handler. Fixed versions are 3.7 and 2.19.6 for the open-source plugin, and the AWS managed service has been updated via service software updates. Users who do not use the direct query feature are not affected. AWS recommends upgrading or applying service software updates promptly and restricting async query access to trusted users until patched.
AI Analysis
Technical Summary
The OpenSearch SQL plugin enables SQL and PPL query capabilities on OpenSearch clusters, including integration with external data sources via Apache Spark. A vulnerability exists in the Flint extension query handler where SQL queries are not sufficiently validated, allowing users with asynchronous query access to bypass the SQL grammar deny list through the direct query endpoint. This affects open-source OpenSearch SQL plugin versions 2.13 to 3.6 and Amazon OpenSearch Service versions 2.13 to 3.5. The issue is resolved in open-source plugin versions 3.7 and 2.19.6, and in the AWS managed service via service software updates. AWS advises upgrading or applying updates and restricting async query access until patched.
Potential Impact
An attacker with asynchronous query access can bypass SQL grammar restrictions, potentially allowing unauthorized or unintended queries through the direct query endpoint. This could lead to execution of queries that should be blocked by the deny list, impacting data security and query integrity. The vulnerability affects both self-managed open-source deployments and AWS managed services. However, users not utilizing the direct query feature are not impacted.
Mitigation Recommendations
For open-source OpenSearch SQL plugin users, upgrade to versions 3.7 or 2.19.6 or later to address the vulnerability. For Amazon OpenSearch Service customers, apply the latest service software update which includes the fix; domains with automatic updates enabled will receive the patch during the next off-peak window. Until patched, restrict asynchronous query access to trusted users only, especially if direct query with external data sources is configured. Users not using the direct query feature are not affected and require no action.
CVE-2026-18428 - OpenSearch SQL Plugin - Async Query Validation Bypass
Description
CVE-2026-18428 is a vulnerability in the OpenSearch SQL plugin that allows users with asynchronous query access to bypass SQL grammar restrictions via the direct query endpoint. This affects both the open-source self-managed OpenSearch SQL plugin versions 2.13 through 3.6 and the AWS managed Amazon OpenSearch Service versions 2.13 through 3.5. The issue arises from insufficient validation in the Flint extension query handler. Fixed versions are 3.7 and 2.19.6 for the open-source plugin, and the AWS managed service has been updated via service software updates. Users who do not use the direct query feature are not affected. AWS recommends upgrading or applying service software updates promptly and restricting async query access to trusted users until patched.
Affected software
pkg:maven/org.opensearch/sql-pluginRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The OpenSearch SQL plugin enables SQL and PPL query capabilities on OpenSearch clusters, including integration with external data sources via Apache Spark. A vulnerability exists in the Flint extension query handler where SQL queries are not sufficiently validated, allowing users with asynchronous query access to bypass the SQL grammar deny list through the direct query endpoint. This affects open-source OpenSearch SQL plugin versions 2.13 to 3.6 and Amazon OpenSearch Service versions 2.13 to 3.5. The issue is resolved in open-source plugin versions 3.7 and 2.19.6, and in the AWS managed service via service software updates. AWS advises upgrading or applying updates and restricting async query access until patched.
Potential Impact
An attacker with asynchronous query access can bypass SQL grammar restrictions, potentially allowing unauthorized or unintended queries through the direct query endpoint. This could lead to execution of queries that should be blocked by the deny list, impacting data security and query integrity. The vulnerability affects both self-managed open-source deployments and AWS managed services. However, users not utilizing the direct query feature are not impacted.
Mitigation Recommendations
For open-source OpenSearch SQL plugin users, upgrade to versions 3.7 or 2.19.6 or later to address the vulnerability. For Amazon OpenSearch Service customers, apply the latest service software update which includes the fix; domains with automatic updates enabled will receive the patch during the next off-peak window. Until patched, restrict asynchronous query access to trusted users only, especially if direct query with external data sources is configured. Users not using the direct query feature are not affected and require no action.
Technical Details
- Classification
- {"confidence":0.88,"severitySource":"default","classifier":"rss-v2"}
- Article Source
- {"url":"https://aws.amazon.com/security/security-bulletins/rss/2026-081-aws/","fetched":true,"fetchedAt":"2026-08-13T17:53:43.416Z","wordCount":306}
Threat ID: 6a7e04a7bf8831d539931c0a
Added to database: 08/13/2026, 17:53:43 UTC
Last enriched: 08/13/2026, 17:53:53 UTC
Last updated: 08/13/2026, 18:38:26 UTC
Views: 4
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