# CVE-2026-73334: Apache Parquet Hadoop: File-controlled KMS URL is forwarded to pluggable KmsClient that skips host validation

> Attackers can send KMS tokens to malicious hosts via file-controlled URLs in Apache Parquet, potentially exposing sensitive keys if host validation is skipped.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** CLEANSTART-2026-AF89785, CLEANSTART-2026-MZ54004, GHSA-wrx6-qm3h-c589

## What is CVE-2026-73334?

CVE-2026-73334 is a high-severity server-side request forgery vulnerability in Apache Parquet Hadoop, published on 9 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Potential problem for users of the org.apache.parquet.crypto.keytools package in Apache Parquet, versions 1.12 to 1.18. 
This package enables users to encrypt Parquet files via an envelope encryption mechanism that wraps (encrypts) data keys via a Key Management Service (KMS). 
On the reader side, the KMS URL can be application-controlled or file-controlled.
If the user does not leverage application control for this parameter, a file-controlled KMS URL is forwarded to a pluggable KmsClient implementation. 
If the pluggable implementation does not perform host validation, a KMS token can be sent to a malicious host set by an attacker in the file.

Before the problem is fixed, users are recommended to leverage application control for KMS URL parameter in readers (versions 1.12-1.18).
After the problem is fixed (presumably in version 1.19), the upgrade will disable file-controlled KMS URL by default. Users of the KMS URL parameter 
will have two options then: leverage application control for KMS URL parameter in readers, or enable file-controlled KMS URL (via a new app parameter).
The latter option will explicitly require (in the new parameter documentation) to validate the KMS URL and use authentication in the custom implementation of the KMS client plug in.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-73334?

It affects 1 product.


Products: Apache Parquet.

## How do I fix CVE-2026-73334?

Upgrade to a fixed version.

## Is CVE-2026-73334 being exploited?

There is no known exploitation of CVE-2026-73334 in the wild and no public exploit code.

## Other vulnerabilities in Apache Parquet Hadoop

- [CVE-2025-46762](https://insights.sbomify.com/CVE-2025-46762/): Apache Parquet Java: Potential malicious code execution from trusted packages in the parquet-avro module when reading an Avro schema from a Parquet file metadata (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73334 and fix it if it is affected.

What it is: CVE-2026-73334 is a high-severity server-side request forgery vulnerability in Apache Parquet Hadoop, published on 9 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-73334 in the wild and no public exploit code.

Affected product: Apache Parquet Hadoop. 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-2026-73334/ (Markdown: https://insights.sbomify.com/CVE-2026-73334/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73334
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73334
- OSV: https://osv.dev/vulnerability/CVE-2026-73334

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73334/
Summaries are generated and may contain mistakes; the official description above is the record.