Vulnerability in Hdfgroup Hdf5

CVE-2026-26199

HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If `H5Iget_name` is invoked on a group id with `0` for the size parameter, it will underflow when trying to place a null terminator in the buffer. This can occur if `H5Iget_name` is invoked in a way where `size` can be forced to zero, and there is important data before the `name` buffer.

EPSS: 0.003 (21.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-26199?
CVE-2026-26199 is a medium-severity vulnerability in Hdfgroup Hdf5, classified under Buffer Underwrite. CVSS score: 6.5/10. Published 2026-07-20.
How severe is CVE-2026-26199?
Medium severity. CVSS v3 base score is 6.5 out of 10.