# CVE-2026-18428: SQL Query Validation Bypass in OpenSearch Direct Query

> Remote authenticated attackers can execute arbitrary code on Spark workers by bypassing SQL validation in the OpenSearch Flint extension.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Aug 2026
- **Updated:** 13 Aug 2026
- **Also known as:** GHSA-3rvx-fcj6-wr45, GHSA-g4jr-343c-fvjm

## What is CVE-2026-18428?

CVE-2026-18428 is a high-severity code injection vulnerability in AWS Opensearch, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A SQL query validation bypass in the Flint extension query handler in the OpenSearch SQL plugin allows a remote authenticated actor with async query access to execute arbitrary code on Apache Spark workers by sending a crafted SQL query to the direct query endpoint.

Weakness: CWE-693 (Protection Mechanism Failure)

## Which versions are affected by CVE-2026-18428?


## How do I fix CVE-2026-18428?

No fix has been published for CVE-2026-18428 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18428 being exploited?

There is no known exploitation of CVE-2026-18428 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18428 and fix it if it is affected.

What it is: CVE-2026-18428 is a high-severity code injection vulnerability in AWS Opensearch, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-18428 in the wild and no public exploit code.

Affected product: AWS Opensearch. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-18428/ (Markdown: https://insights.sbomify.com/CVE-2026-18428/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18428
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18428
- OSV: https://osv.dev/vulnerability/CVE-2026-18428

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18428/
Summaries are generated and may contain mistakes; the official description above is the record.