CVE-2026-19026: Null Dereference

Description

H5Z__filter_nbit in H5Znbit.c in HDF5 through 2.3.0 dereferences cd_values[0] through cd_values[4] without validating that cd_values is non-NULL or that cd_nelmts is at least 5, the fixed size of the filter's header. This allows attackers to cause a denial of service via a crafted HDF5 file that stores the N-Bit filter pipeline message with zero client-data values, opened and read via H5Dread, e.g. by the h5ls or h5repack tools.

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Weakness Type (CWE)

CWE-476 CWE-476

CWE-1284 CWE-1284

References

Other References

https://github.com/HDFGroup/hdf5/issues/6489 https://github.com/HDFGroup/hdf5/issues/6492 https://github.com/HDFGroup/hdf5/pull/6497

Frequently Asked Questions

What is CVE-2026-19026? +

H5Z__filter_nbit in H5Znbit.c in HDF5 through 2.3.0 dereferences cd_values[0] through cd_values[4] without validating that cd_values is non-NULL or that cd_nelmts is at least 5, the fixed size of the filter's header. This allows attackers to cause a denial of service via a crafted HDF5 file that stores the N-Bit filter pipeline message with zero client-data values, opened and read via H5Dread, e.g. by the h5ls or h5repack tools.

How do I check if I'm vulnerable to CVE-2026-19026? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-19026