CVE-2026-26199

Buffer underflow in `H5Iget_name `/`H5G_get_name` if size is zero

MEDIUM
6.5
CVSS Score
Published: July 20, 2026 at 02:59 PM UTC
Updated: October 24, 2026 at 08:10 PM UTC
1 product affected across 1 vendorHDF5

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.1.0<= 1.14.6
Affected range stops below 2.1.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/HDFGroup/hdf5/security/advisories/GHSA-5c6x-jmgf-f5vc

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-124

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