CVE-2026-19025 HDF5 divide-by-zero (SIGFPE) via mismatched chunk-layout dimensionality and dataspace rank on dataset open
Attackers can cause a denial of service via divide-by-zero crash in HDF5 library by opening crafted files with mismatched chunk and dataspace ranks.
- 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-2026-19025?
CVE-2026-19025 is a medium-severity denial of service vulnerability in The HDF Group HDF5, published on 5 Aug 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
H5O__layout_decode in H5Olayout.c in HDF5 through 2.3.0 does not validate that a chunked dataset's stored chunk-layout dimensionality matches its dataspace rank when an existing dataset is opened, whereas this check is performed only at dataset-creation time. This allows attackers to cause a denial of service (divide-by-zero and application crash in H5S__hyper_iter_get_seq_list in src/H5Shyper.c) via a crafted HDF5 file with mismatched chunk/dataspace ranks that is opened and read via H5Dopen2 and H5Dread, e.g. by the h5repack tool.
Weakness: CWE-369
Which versions are affected by CVE-2026-19025?
How do I fix CVE-2026-19025?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-19025 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-19025 exists.
Sources
Also known as AZL-94490, DEBIAN-CVE-2026-19025, ECHO-5e92-f075-6b1a, GHSA-546v-jw2p-gc8p, UBUNTU-CVE-2026-19025.