CVE-2026-26200 HDF5 Affected by H5T__conv_struct_opt Heap Buffer Overflow
An attacker can trigger a heap buffer overflow in HDF5 by providing a malicious h5 file, causing denial of service or potential code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-26200?
CVE-2026-26200 is a high-severity memory corruption vulnerability in Hdfgroup Hdf5, published on 19 Feb 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
HDF5 is software for managing data. Prior to version 1.14.4-2, an attacker who can control an `h5` file parsed by HDF5 can trigger a write-based heap buffer overflow condition. This can lead to a denial-of-service condition, and potentially further issues such as remote code execution depending on the practical exploitability of the heap overflow against modern operating systems. Real-world exploitability of this issue in terms of remote-code execution is currently unknown. Version 1.14.4-2 fixes the issue.
Which versions are affected by CVE-2026-26200?
It affects 1 product.
Products include Hdfgroup Hdf5.
How do I fix CVE-2026-26200?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-26200 being exploited?
There is no known exploitation of CVE-2026-26200 in the wild and no public exploit code.
Other vulnerabilities in Hdfgroup Hdf5
Sources
Also known as DEBIAN-CVE-2026-26200, ECHO-a777-bf3c-cf20, GHSA-5p2m-j456-9mr2, JLSEC-2026-352, UBUNTU-CVE-2026-26200.