CVE-2026-26200

Modified Modified - Updated After Analysis

Heap Buffer Overflow in HDF5 Allows Denial of Service

Publication date: 2026-02-19

Last updated on: 2026-06-30

Assigner: GitHub, Inc.

Description

HDF5 is software for managing data. Prior to version 1.14.4-2, an attacker who can control an `h5` file parsed by HDF5 can trigger a write-based heap buffer overflow condition. This can lead to a denial-of-service condition, and potentially further issues such as remote code execution depending on the practical exploitability of the heap overflow against modern operating systems. Real-world exploitability of this issue in terms of remote-code execution is currently unknown. Version 1.14.4-2 fixes the issue.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-02-19

Last Modified

2026-06-30

Generated

2026-07-06

AI Q&A

2026-02-19

EPSS Evaluated

2026-07-05

NVD

CVE-2026-26200

EUVD

EUVD-2026-7979

Affected Vendors & Products

Vendor	Product	Version / Range
hdfgroup	hdf5	to 1.14.4.2 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-131	The product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.
CWE-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This vulnerability exists in HDF5 software versions prior to 1.14.4-2. It occurs when an attacker controls an 'h5' file that is parsed by HDF5, which can trigger a write-based heap buffer overflow. This overflow can cause a denial-of-service condition and may potentially allow further issues such as remote code execution, although the real-world exploitability for remote code execution is currently unknown.

Impact Analysis

The vulnerability can lead to a denial-of-service condition by causing a heap buffer overflow when processing a malicious 'h5' file. Additionally, there is a potential risk of remote code execution depending on how exploitable the heap overflow is on modern operating systems, which could allow an attacker to execute arbitrary code.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

To mitigate this vulnerability, you should upgrade HDF5 to version 1.14.4-2 or later, as this version contains the fix for the heap buffer overflow issue.

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