Bug 2502861

Summary: CVE-2026-26197 hdf5: HDF5: Out-of-bounds read due to corrupted file can lead to denial of service [fedora-all]
Product: [Fedora] Fedora Reporter: Ganesh <gnaik>
Component: hdf5Assignee: Orion Poplawski <orion>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: igor.raits, orion, sagitterghostproton.me, scitech-bugs
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["004c8972-c6e9-4baf-890e-119a11984f3d"]}
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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:    
Bug Blocks: 2502846    

Description Ganesh 2026-07-20 16:33:00 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If a file is corrupted such that an array datatype's size, the number of elements, and the element size  are not in agreement it can trigger an out of bounds read. The array datatype stores the full size of the datatype (`dt->shared->size`) separately from the number of elements (`dt->shared->u.array.nelem`) and the element size (`dt->shared->parent->shared->size`). If any one of these are corrupted so that they don't align with the others (element size * nelem = full size), it can lead to an out of bounds read. Depending on what is corrupted, it can alter the type of out of bounds read triggered. The vulnerability is present only in files that have been maliciously altered, as its generally not possible to independently alter the full size of the datatype, the element count and the element size. As such, this is only present if a malicious actor is altering files, and won't appear in regular usage.