What is CVE-2026-34734?

CVE-2026-34734 is a high-severity vulnerability in Hdfgroup Hdf5, classified under Use After Free. CVSS score: 7.8/10. Published 2026-04-09.

How severe is CVE-2026-34734?

High severity. CVSS v3 base score is 7.8 out of 10.

Use After Free in Hdfgroup Hdf5

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…

Vulnerability class: Use-After-Free

EPSS: 0.000 (5.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Hdfgroup Hdf5 — versions <= 1.14.1-2

Weakness classification (CWE)

CWE-416 — Use After Free

References

https://github.com/HDFGroup/hdf5/security/advisories/GHSA-w7v2-9cmr-pwwj (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-34734?: CVE-2026-34734 is a high-severity vulnerability in Hdfgroup Hdf5, classified under Use After Free. CVSS score: 7.8/10. Published 2026-04-09.
How severe is CVE-2026-34734?: High severity. CVSS v3 base score is 7.8 out of 10.