CVE-2025-6818 HDF5 H5Ochunk.c H5O__chunk_protect heap-based overflow
A local attacker can trigger a heap-based buffer overflow in the HDF5 library, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-6818?
CVE-2025-6818 is a medium-severity memory corruption vulnerability in Hdfgroup Hdf5, published on 28 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability, which was classified as problematic, was found in HDF5 1.14.6. Affected is the function H5O__chunk_protect of the file /src/H5Ochunk.c. The manipulation leads to heap-based buffer overflow. An attack has to be approached locally. The exploit has been disclosed to the public and may be used.
Which versions are affected by CVE-2025-6818?
It affects 1 product.
Products include Hdfgroup Hdf5.
How do I fix CVE-2025-6818?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-6818 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-6818 exists.
Other vulnerabilities in Hdfgroup Hdf5
Sources
Also known as AZL-64410, AZL-64434, DEBIAN-CVE-2025-6818, ECHO-a463-9e81-4f5c, GHSA-mgf6-wvxv-hr92, JLSEC-2026-345 and 1 more.