Vulnerability · Published Aug 5, 2026 · Assigned by HDFG
CVE-2026-19023HDF5 h5dump Untrusted Pointer Dereference in Binary Output of Variable-Length String Datasets
Medium 6.8
In plain English
A medium-severity security flaw in HDF5 from The HDF Group. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).
Official description
Untrusted pointer dereference in the render_bin_output function in the h5dump tool in HDF5 before 2.3.0 allows attackers to cause a denial of service via a variable-length string dataset with more than one element dumped in binary mode, which corrupts the per-element stride calculation and causes subsequent elements to be read from a misaligned offset and dereferenced as a pointer.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | hdf5 | no fix listed | DEBIAN-CVE-2026-19023 |
| Debian:13 | hdf5 | no fix listed | DEBIAN-CVE-2026-19023 |
| Debian:14 | hdf5 | no fix listed | DEBIAN-CVE-2026-19023 |
| Ubuntu:22.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2026-19023 |
| Ubuntu:24.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2026-19023 |
| Ubuntu:26.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2026-19023 |
| Ubuntu:26.10 | hdf5 | no fix listed | UBUNTU-CVE-2026-19023 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| The HDF Group | HDF5 | <= 2.3.0 |
Weakness: CWE-822 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N