Vulnerability Description
The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 through 2.3.0 advance a read index into the compressed chunk buffer without bounding it against the buffer's actual size. This allows attackers to cause an out-of-bounds heap read, and in constrained cases disclosure of adjacent heap memory into decompressed dataset values, via a crafted HDF5 file whose N-Bit filter parameters describe more decompressed data than the stored compressed chunk actually contains, triggered via H5Dread, e.g. by the h5ls or h5repack tools.
Related Weaknesses (CWE)
References
- https://github.com/HDFGroup/hdf5/issues/6489
- https://github.com/HDFGroup/hdf5/issues/6492
- https://github.com/HDFGroup/hdf5/pull/6497
- https://github.com/HDFGroup/hdf5/issues/6489
FAQ
What is CVE-2026-19027?
CVE-2026-19027 is a documented vulnerability. The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 through 2.3.0 advance a read index into the compressed chunk bu...
How severe is CVE-2026-19027?
CVSS scoring is not yet available for CVE-2026-19027. Check NVD for updates.
Is there a patch for CVE-2026-19027?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.