CVE-2026-19024 and is rated High severity with a CVSS score of 8.2. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
What to do next
Remediation and response
Microsoft Security Response Center guidance
Vendor revision: Sep 25, 2026
Release Notes
CISA KEVNot listedBased on the latest collected catalog
EPSS0.2%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-19024?
NULL pointer dereference in H5Pget_fill_value in HDF5 before 2.3.0 allows attackers to cause a denial of service via a dataset whose version 1 or 2 fill value message has the "defined" flag set together with a negative size field, which is not normalized to the library's "undefined" sentinel and reaches H5T_path_find with a NULL datatype.