CVE-2026-19027HDF5 out-of-bounds heap read in N-Bit filter decompression
Updated under an hour ago ()
Does this affect you?
It affects The HDF Group HDF5. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 prior to 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.
- CVSS
- 6.9 MEDIUM (v4.0, CNA)CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
- Weakness (CWE)
- CWE-125
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- HDFG
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 6, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
The HDF Group HDF5 hdf_group:hdf5 (from the name) | through 2.3.0 | CNA record |
References
- https://github.com/HDFGroup/hdf5/pull/6497
- https://github.com/HDFGroup/hdf5/issues/6489
- https://github.com/HDFGroup/hdf5/issues/6492
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.