Bug 2511851 (CVE-2026-19026)

Summary: CVE-2026-19026 hdf5: HDF5: Denial of service via crafted HDF5 file
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: bbrownin
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in HDF5. A remote attacker could craft a malicious HDF5 file that, when opened and read, would cause an application using the HDF5 library to crash. This issue stems from improper validation of input data within the N-Bit filter, leading to a denial of service (DoS) and impacting the availability of services that process these files.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 2515533, 2515534    
Bug Blocks:    

Description OSIDB Bzimport 2026-08-05 23:01:17 UTC 
H5Z__filter_nbit in H5Znbit.c in HDF5 through 2.3.0 dereferences cd_values[0] through cd_values[4] without validating that cd_values is non-NULL or that cd_nelmts is at least 5, the fixed size of the filter's header. This allows attackers to cause a denial of service via a crafted HDF5 file that stores the N-Bit filter pipeline message with zero client-data values, opened and read via H5Dread, e.g. by the h5ls or h5repack tools.