CVE-2026-19027: medium-severity vulnerability in The HDF Group HDF5
HDF5 out-of-bounds heap read in N-Bit filter decompression
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.9epss 0.2%
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:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
The HDF Group · HDF5Related CVEs — The HDF Group HDF5
In the same product, most dangerous first.
CVE-2026-92627MEDIUMHeap Use-After-Free in H5T__conv_f_fEPSS 0.2%CVE-2026-19028MEDIUMHDF5 integer underflow in Fletcher32 filter leads to massive out-of-bounds readEPSS 0.2%CVE-2026-19026MEDIUMNbit filter NULL/short parameter-array dereferenceEPSS 0.2%CVE-2026-19024HIGHHDF5 H5Pget_fill_value NULL Pointer Dereference via Malformed Fill Value MessageEPSS 0.2%CVE-2026-19025MEDIUMHDF5 divide-by-zero (SIGFPE) via mismatched chunk-layout dimensionality and dataspace rank on dataset openEPSS 0.2%CVE-2026-19023MEDIUMHDF5 h5dump Untrusted Pointer Dereference in Binary Output of Variable-Length String DatasetsEPSS 0.2%