CVE-2025-6856
CSIRTS triage
- What
- The H5FL.c file contains a use-after-free vulnerability in the H5FL__reg_gc_list function.
- Who is affected
- Applications using HDF5 libraries that process crafted HDF5 files.
- Urgency
- Low severity (CVSS 3.3); limited exploitability but memory corruption is possible.
- Action
- Update HDF5 to a patched version addressing the use-after-free in H5FL__reg_gc_list.
AI-assisted analysis generated from the source advisory — verify against the original.
⚡ Watch CVE-2025-6856
Get an email if CVE-2025-6856 is added to CISA KEV, gains public exploit code, or a new advisory cites it — max one per day, one-click unsubscribe.
Exploitation outlook
- Low exploitation risk0.20% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 10% of all EPSS-scored CVEs.
Advisory coverage (1)
- lowCVE-2025-6856: HDF5 H5FL.c H5FL__reg_gc_list use after freemsrc · 2026-08-06
External references
Embed the live status
— this badge updates automatically when the KEV or exploit status changes. How to embed it →
[](https://www.csirts.com/cve/CVE-2025-6856)