Vulnerability · Published Jun 29, 2025 · Assigned by VulDB
CVE-2025-6856HDF5 H5FL.c H5FL__reg_gc_list use after free
Low 3.3
In plain English
A low-severity use-after-free in HDF5. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)3.3Low
Exploit odds (30 days)0.3%top 83.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
A vulnerability, which was classified as problematic, was found in HDF5 1.14.6. Affected is the function H5FL__reg_gc_list of the file src/H5FL.c. The manipulation leads to use after free. Attacking locally is a requirement. The exploit has been disclosed to the public and may be used.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | hdf5 | no fix listed | DEBIAN-CVE-2025-6856 |
| Debian:13 | hdf5 | no fix listed | DEBIAN-CVE-2025-6856 |
| Debian:14 | hdf5 | 2.1.0+repack-1 | DEBIAN-CVE-2025-6856 |
| Ubuntu:22.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2025-6856 |
| Ubuntu:24.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2025-6856 |
| Ubuntu:25.10 | hdf5 | no fix listed | UBUNTU-CVE-2025-6856 |
| Ubuntu:26.04:LTS | hdf5 | no fix listed | UBUNTU-CVE-2025-6856 |
| Ubuntu:26.10 | hdf5 | no fix listed | UBUNTU-CVE-2025-6856 |
Affected products (as reported)
Weakness: CWE-416, CWE-119 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
References
- VDB-314328 | HDF5 H5FL.c H5FL__reg_gc_list use after free vdb-entry, technical-description
- VDB-314328 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- Submit #602528 | HDFGroup HDF5 hdf5 1.14.6 (commit 17c16b6) Use After Free third-party-advisory
- https://github.com/HDFGroup/hdf5/issues/5574 issue-tracking
- https://github.com/user-attachments/files/20623417/hdf5_crash_6.txt exploit