Vulnerability · Published Jul 27, 2026 · Assigned by HDFG
CVE-2026-17573Double Free in H5D__chunk_copy() in HDF5 via a Crafted Chunk-Index Size Field
Medium 4.0
In plain English
A medium-severity double free 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 4% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 4.0)4.0Medium
Exploit odds (30 days)0.2%top 95.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
A double free vulnerability was discovered in the HDF5 library. Processing a crafted HDF5 file containing an oversized chunk size field via h5repack may cause the application to abort due to a double free.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | hdf5 | no fix listed | DEBIAN-CVE-2026-17573 |
| Debian:13 | hdf5 | no fix listed | DEBIAN-CVE-2026-17573 |
| Debian:14 | hdf5 | 2.1.0+repack-1 | DEBIAN-CVE-2026-17573 |
| Ubuntu:22.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2026-17573 |
| Ubuntu:24.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2026-17573 |
| Ubuntu:26.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2026-17573 |
| Ubuntu:26.10 | hdf5 | no fix listed | UBUNTU-CVE-2026-17573 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| The HDF Group | HDF5 | <= 2.1.1 |
Weakness: CWE-415 · Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U