CVE-2026-34734: Hdfgroup HDF5

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Hdfgroup HDF5: before 1.14.1-2 (fixed in 1.14.1-2)

Published 2026-04-09. Last modified 2026-07-15.