CVE-2026-26199

unknowncovered by 2 sourcesfirst seen 2026-07-14

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.

CSIRTS triage

What: A buffer underflow issue in certain HDF5 functions has been identified.
Who is affected: No specific deployments or versions are mentioned.
Urgency: The urgency is unclear as the severity is listed as unknown.
Action: No specific action is provided.

AI-assisted analysis generated from the source advisory — verify against the original.

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Exploitation outlook

Low exploitation risk0.26% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 17% of all EPSS-scored CVEs.

Advisory coverage (2)

unknownCVE-2026-26199: HDF5 is a high-performance library and a file format specification that implements the HDF5 da…nvd · 2026-07-20
unknownCVE-2026-26199: Buffer underflow in `H5Iget_name `/`H5G_get_name` if size is zeromsrc · 2026-07-14

External references

NVD record for CVE-2026-26199

CVE.org record

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