CVE-2026-26199

MEDIUMCVSS 6.5/10EPSS 0.28%

Last modified

CVE-2026-26199 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 0.28% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
6.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

CVSS 4.0
5.9/10

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.28%

20.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
HdfgroupHdf5< 2.1.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is 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.
How severe is CVE-2026-26199?
CVE-2026-26199 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.28% probability of exploitation in the next 30 days.
How do I fix CVE-2026-26199?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST