Quick answers
- Is CVE-2026-34734 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-34734 being exploited in the wild.
- How severe is CVE-2026-34734?
- High severity, with a CVSS score of 7.8, published 9 April 2026.
- Which products and versions are affected?
- HDFGroup hdf5 <= 1.14.1-2; Red Hat Red Hat Enterprise Linux AI (RHEL AI) 3 affected.
- Is there a fix for CVE-2026-34734?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-34734 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-34734?
- Check whether you run Hdfgroup Hdf5. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A heap use-after-free vulnerability exists in the h5dump helper utility of HDF5 versions 1.14.1-2 and earlier. The flaw occurs when a freed object, originally allocated by H5D__typeinfo_init_phase3 and freed by H5D__typeinfo_term, is subsequently referenced in a memmove call within H5T__conv_struct. An attacker can exploit this by providing a malicious HDF5 (.h5) file. While the primary attack vector requires a user to parse the file with h5dump (UI:R), server-side processes automatically parsing attacker-controlled files may also be at risk. Successful exploitation can lead to arbitrary code execution or a denial-of-service (DoS) condition.
Affected products
- HDFGroup hdf5 <= 1.14.1-2
- Red Hat Red Hat Enterprise Linux AI (RHEL AI) 3 affected
Timeline
- 2026-04-09: disclosed: Initial disclosure by HDFGroup and Red Hat
- 2026-04-09: advisory: GitHub Advisory GHSA-w7v2-9cmr-pwwj published