CVE-2026-34734: high-severity vulnerability in HDFGroup hdf5
HDF5: H5T__conv_struct Use After Free
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.8epss 0.2%
HDF5 is software for managing data. In 1.14.1-2 and earlier, a heap-use-after-free was found in the h5dump helper utility. An attacker who can supply a malicious h5 file can trigger a heap use-after-free. The freed object is referenced in a memmove call from H5T__conv_struct. The original object was allocated by H5D__typeinfo_init_phase3 and freed by H5D__typeinfo_term.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected products
HDFGroup · hdf5Related CVEs — HDFGroup hdf5
In the same product, most dangerous first.
CVE-2026-26200HIGHHDF5 Affected by H5T__conv_struct_opt Heap Buffer OverflowEPSS 0.4%CVE-2026-26197MEDIUMArray full size, element count, and element size are not checked to make sure they match in H5Odtype.cEPSS 0.4%CVE-2026-26199MEDIUMBuffer underflow in `H5Iget_name `/`H5G_get_name` if size is zeroEPSS 0.4%CVE-2026-29043MEDIUMHDF5 H5T__ref_mem_setnull Heap Buffer OverflowEPSS 0.2%