CVE-2026-26199 | HDF5 is a high-performance library and a file format specifi… | CVSS 5.9 MEDIUM

Description

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.

Metadata

CVE ID: CVE-2026-26199
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-02-11 19:56 UTC
Published: 2026-07-20 14:59 UTC
Last updated: 2026-07-20 18:56 UTC
Primary CWE: CWE-124
CWE-124: Buffer Underwrite ('Buffer Underflow')
Vendor / Product: HDFGroup / hdf5
Sources: cve.org · NVD

Severity & Metrics

5.9 MEDIUM CVSS 4.0

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: no
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
HDFGroup	hdf5	—	<= 1.14.6

Weakness (CWE)

CWE	Source	Description
CWE-124	cna	CWE-124: Buffer Underwrite ('Buffer Underflow')

CVSS scores (1)

Score	Severity	Version	Source	Vector
5.9	MEDIUM	4.0	cna	CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References (2)

https://github.com/HDFGroup/hdf5/security/advisories/GHSA-5c6x-jmgf-f5vc https://github.com/HDFGroup/hdf5/security/advisories/GHSA-5c6x-jmgf-f5vc
https://github.com/HDFGroup/hdf5/blob/develop/src/H5Gname.c#L474 https://github.com/HDFGroup/hdf5/blob/develop/src/H5Gname.c#L474