CVE-2026-19024: The Hdf Group HDF5

High severity, CVSS 8.2. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• The Hdf Group HDF5: up to and including 2.3.0

Published 2026-08-05. Last modified 2026-08-31.