Description
Heap-based buffer overflow in the SOHM list-index deserialization code in HDF5 through 2.1.1 on all platforms allows attackers to cause a denial of service (crash) via a crafted HDF5 file whose shared-message list index declares a num_messages count exceeding list_max, triggering out-of-bounds heap reads and writes in H5SM__cache_list_deserialize and H5SM__cache_list_verify_chksum.
Affected products
hdfgroup: hdf5
References1
- github.com/HDFGroup/hdf5/issues/6501 Issue Tracking
Metrics
- CVSS 3.1
-
5.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - CVSS 4.0
-
5.5
MEDIUM
Score source: CNA
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:H/SC:N/SI:L/SA:H/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 3 · as of 13 November 2026
- CWE
- CWE-125CWE-787
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.