CVE-2026-34734

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

7.8CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 8% of CVEs (scores of 2026-10-26)

CWEs

CWE-416, CWE-825

Published

2026-04-09

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• hdfgroup:hdf5

References

• https://github.com/HDFGroup/hdf5/security/advisories/GHSA-w7v2-9cmr-pwwj
• https://access.redhat.com/security/cve/CVE-2026-34734
• https://bugzilla.redhat.com/show_bug.cgi?id=2457034
• https://github.com/HDFGroup/hdf5/security/advisories/GHSA-w7v2-9cmr-pwwj
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34734.json

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