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Vulnerability record · CVE-2026-34734 · published 9 April 2026

CVE-2026-34734: Hdfgroup hdf5 use after free vulnerability

Hdfgroup · Hdf5

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.

7.8 CVSS 3.1 High EPSS 0.19% · top 92.1% CWE-416 · Use after freeCWE-825 · CWE-825
7.8CVSS 3.1 base score
0.19%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
5References, 2 tagged exploit
15 Jul 2026Last modified by NVD

Description

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

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/HDFGroup/hdf5/security/advisories/GHSA-w7v2-9cmr-pwwj ExploitVendor Advisory
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 ExploitVendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34734.json

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2024-32608Hdfgroup hdf5 out-of-bounds write vulnerabilityHDF5 library through 1.14.3 has memory corruption in H5A__close resulting in the corruption of the instruction pointer and causing denial of service …EPSS 0.67%9.8CVE-2024-33874Hdfgroup hdf5 classic buffer overflow vulnerabilityHDF5 Library through 1.14.3 has a heap buffer overflow in H5O__mtime_new_encode in H5Omtime.c.EPSS 0.93%9.8CVE-2024-32621Hdfgroup hdf5 heap-based buffer overflow vulnerabilityHDF5 Library through 1.14.3 contains a heap-based buffer overflow in H5HG_read in H5HG.c (called from H5VL__native_blob_get in H5VLnative_blob.c), re…EPSS 0.93%9.8CVE-2024-32611Hdfgroup hdf5 use of uninitialized resource vulnerabilityHDF5 Library through 1.14.3 may use an uninitialized value in H5A__attr_release_table in H5Aint.c.EPSS 0.95%9.8CVE-2024-32615Hdfgroup hdf5 out-of-bounds write vulnerabilityHDF5 Library through 1.14.3 contains a heap-based buffer overflow in H5Z__nbit_decompress_one_byte in H5Znbit.c, caused by the earlier use of an init…EPSS 1.1%9.8CVE-2024-29164Hdfgroup hdf5 stack-based buffer overflow vulnerabilityHDF5 through 1.14.3 contains a stack buffer overflow in H5R__decode_heap, resulting in the corruption of the instruction pointer and causing denial o…EPSS 0.86%9.8CVE-2024-29159Hdfgroup hdf5 classic buffer overflow vulnerabilityHDF5 through 1.14.3 contains a buffer overflow in H5Z__filter_scaleoffset, resulting in the corruption of the instruction pointer and causing denial …EPSS 0.92%9.8CVE-2024-29157Hdfgroup hdf5 heap-based buffer overflow vulnerabilityHDF5 through 1.14.3 contains a heap buffer overflow in H5HG_read, resulting in the corruption of the instruction pointer and causing denial of servic…EPSS 0.90%

Source: NIST National Vulnerability Database (record CVE-2026-34734), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.