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

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.

Published: 2026-01-26 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-27821 is rated Moderate Risk (48.1/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.86%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-27821

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-23 0.80% 0.86% +0.06%
2 2026-06-15 0.05% 0.80% +0.76%
3 2026-05-23 — 0.05% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-27821

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 3.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-27821

GitHub Security Advisory for CVE-2025-27821

GHSA-92cc-952p-v8rh · Severity: high · Ecosystem: maven — Apache Hadoop HDFS Native Client has Out-of-bounds Write Vulnerability

Affected software / configurations for CVE-2025-27821

Vendor Product Version Raw CPE
apache hadoop >= 3.2.0, < 3.4.2 cpe:2.3:a:apache:hadoop:*:*:*:*:*:*:*:*

References for CVE-2025-27821

cvelogic Threat Intelligence