CVE-2026-17573 in HDF5
Summary
by MITRE • 07/27/2026
A double free vulnerability was discovered in the HDF5 library. Processing a crafted HDF5 file containing an oversized chunk size field via h5repack may cause the application to abort due to a double free.
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Analysis
by VulDB Data Team • 07/27/2026
The double free vulnerability in the HDF5 library represents a critical memory corruption issue that can lead to arbitrary code execution or application crashes. This vulnerability specifically manifests when processing malformed HDF5 files through the h5repack utility, where an oversized chunk size field triggers improper memory management. The flaw occurs during the parsing and handling of HDF5 file structures, particularly affecting the library's internal memory allocation and deallocation mechanisms. Such vulnerabilities are classified under CWE-415 as double free conditions that can result in heap corruption and unpredictable application behavior.
The technical implementation of this vulnerability stems from inadequate input validation within the HDF5 library's chunk size parsing logic. When h5repack encounters a crafted HDF5 file with an oversized chunk size field, the library fails to properly validate the size parameters before proceeding with memory operations. This lack of bounds checking allows maliciously constructed files to manipulate the internal heap management routines, causing the same memory block to be freed twice during the processing sequence. The vulnerability is particularly dangerous because it can be exploited remotely through file processing operations, making it a significant threat to applications that handle untrusted HDF5 data.
Operationally, this vulnerability impacts any system or application that utilizes the HDF5 library for data storage and retrieval, especially those processing external or user-supplied HDF5 files. The double free condition can result in complete application termination, memory corruption, or potentially enable remote code execution depending on the exploitation context. Security implications extend beyond simple denial of service, as attackers could leverage this flaw to execute arbitrary code on systems processing affected files. Organizations using HDF5 libraries in scientific computing, data analysis platforms, and storage applications face elevated risk levels when dealing with untrusted data inputs.
Mitigation strategies should focus on immediate patch application from the HDF5 library maintainers, alongside input validation measures that restrict chunk size parameters during file processing. System administrators should implement strict file validation procedures for all incoming HDF5 data, particularly in multi-user environments where untrusted inputs are common. The vulnerability aligns with ATT&CK technique T1059.007 for execution through file processing and represents a classic heap-based memory corruption exploit. Organizations should also consider implementing sandboxing mechanisms around HDF5 processing utilities and monitoring for abnormal memory allocation patterns that might indicate exploitation attempts. Regular security assessments of HDF5-dependent applications are crucial to identify potential attack vectors and ensure proper implementation of defensive controls against similar memory management vulnerabilities.