Bug 2511860 (CVE-2026-19027)

Summary: CVE-2026-19027 hdf5: HDF5: Information disclosure and 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 widely used data management library. This vulnerability allows an attacker to craft a malicious HDF5 file that, when processed, can cause the application to read beyond its allocated memory. This out-of-bounds read could lead to the disclosure of sensitive information or result in a denial of service (DoS), making the application unavailable.
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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: 2516019, 2516020    
Bug Blocks:    

Description OSIDB Bzimport 2026-08-05 23:21:36 UTC 
The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 through 2.3.0 advance a read index into the compressed chunk buffer without bounding it against the buffer's actual size. This allows attackers to cause an out-of-bounds heap read, and in constrained cases disclosure of adjacent heap memory into decompressed dataset values, via a crafted HDF5 file whose N-Bit filter parameters describe more decompressed data than the stored compressed chunk actually contains, triggered via H5Dread, e.g. by the h5ls or h5repack tools.