Bug 2511850 (CVE-2026-19025)

Summary:	CVE-2026-19025 hdf5: HDF5: Denial of Service due to malformed chunk data in files
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	bbrownin
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in HDF5. An attacker can craft a malicious HDF5 file that, when opened and read by an application, exploits a validation bypass. This bypass, related to mismatched chunk-layout dimensionality and dataspace rank, leads to a divide-by-zero error, causing a denial of service (DoS) and application crash.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2515521, 2515522
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Description OSIDB Bzimport 2026-08-05 23:01:14 UTC

H5O__layout_decode in H5Olayout.c in HDF5 through 2.3.0 does not validate that a chunked dataset's stored chunk-layout dimensionality matches its dataspace rank when an existing dataset is opened, whereas this check is performed only at dataset-creation time. This allows attackers to cause a denial of service (divide-by-zero and application crash in H5S__hyper_iter_get_seq_list in src/H5Shyper.c) via a crafted HDF5 file with mismatched chunk/dataspace ranks that is opened and read via H5Dopen2 and H5Dread, e.g. by the h5repack tool.