CVE-2025-6516: HDF5 · Heap-based Buffer Overflow
Affects HDF5Source CVE Database V5
Not known to be exploited · CVSS 4.8 Medium.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 31% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 23 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHubhdfgroup/hdf5pkg:github/hdfgroup/hdf5Other threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Immediately audit all systems using HDF5 versions 1.14.0 through 1.14.6 to identify vulnerable instances.
Restrict local access to systems running HDF5 to trusted users only, minimizing the risk of local exploitation.
Implement strict access controls and monitoring on shared systems where HDF5 is used to detect suspicious local activities.
Isolate critical systems using HDF5 from general user environments to reduce attack surface.
Apply virtual patching techniques such as runtime application self-protection (RASP) or memory protection mechanisms to mitigate heap overflow risks until official patches are released.
Monitor vendor and community channels for official patches or updates addressing this vulnerability and apply them promptly once available.
Conduct regular integrity checks on HDF5-managed data to detect corruption early.
Educate local users about the risks of executing untrusted code or files on systems with HDF5 to prevent inadvertent exploitation.
Description
A vulnerability has been found in HDF5 up to 1.14.6 and classified as critical. This vulnerability affects the function H5F_addr_decode_len of the file /hdf5/src/H5Fint.c. The manipulation leads to heap-based buffer overflow. An attack has to be approached locally. The exploit has been disclosed to the public and may be used.