Which versions of HDF5 are affected by EUVD-2026-93991?

A heap-based buffer overflow in the HDF5 data library (CVE-2026-106547, CVSS 8.5) lets a crafted HDF5 file corrupt memory in any application that opens it, crashing the process and potentially…. A patch is available.

How to fix or mitigate EUVD-2026-93991?

Within 24 hours, inventory every system, container image, and pipeline that links or bundles HDF5 - including direct C/C++/Fortran consumers as well as wrappers such as h5py, PyTables, and commercial analytics or simulation stacks - and record the exact library version in each, flagging anything below HDF5 2.2.0 as affected; in parallel, suspend automatic or scheduled ingestion of untrusted, third-party, or externally sourced HDF5 files into unisolated processes and route any parsing that must continue through a disposable, least-privilege, no-network-egress sandbox. Within 7 days, stand up that sandboxed parse-and-convert tier as the standard path for all externally sourced HDF5 inputs, validate or re-serialize files in a contained environment before they reach production pipelines, add monitoring and alerting for abnormal process crashes or terminations in ingest workers, and open a vendor tracking item with The HDF Group to obtain a definitive fix timeline. Within 30 days, plan and stage an upgrade of all affected deployments to HDF5 2.2.0 or later as the target remediation baseline, since the vendor advisory scopes the vulnerable code to releases prior to 2.2.0; where h5py, PyTables, or downstream applications bundle their own HDF5 build, schedule coordinated upgrades so the embedded library is not left behind, and apply equivalent isolation and input-validation controls to any long-lived legacy pipeline that cannot be upgraded on that timeline.

HDF5 EUVD-2026-93991

Q: What is the CVSS score of EUVD-2026-93991?

EUVD-2026-93991 has a CVSS 4.0 base score of 8.5 (High). CVSS vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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 exploitation probability: 0.2%.

| CVE-2026-106547 HIGH

Heap-based Buffer Overflow (CWE-122)

2026-10-06 HDFG

GHSA-p24g-8x6r-2v93

RCE Buffer Overflow Heap Overflow Hdf5 The Hdf Group

8.5

CVSS 4.0 · Vendor: HDFG

Severity by source

Vendor (HDFG) PRIMARY

8.5 HIGH

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/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

vuln.today AI

7.8 HIGH

File must be opened/read by the victim application, so AV:L and UI:R; no privileges needed (PR:N); attacker-controlled heap corruption yields full C/I/A impact though code execution is only 'possible.'

3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (HDFG).

CVSS VectorVendor: HDFG

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Scope

Lifecycle Timeline

Patch available

Oct 06, 2026 - 22:20 EUVD

Analysis Generated

Oct 06, 2026 - 21:41 vuln.today

CVE Published

Oct 06, 2026 - 20:14 cve.org

HIGH 8.5

DescriptionCVE.org

A heap-based buffer overflow in H5VM_array_fill() in src/H5VM.c in HDF5 before 2.2.0 lets a remote attacker cause an application crash and possibly execute arbitrary code with a crafted HDF5 file. When a dataset's unallocated chunks are read, H5D__fill_init() fills the fill-value buffer from datatype and dataspace metadata in the file. If that metadata is inconsistent with the buffer's allocated size, the write goes past the end of the buffer. The attacker can control the content written through the fill value stored in the file.

AnalysisAI

Heap-based buffer overflow in HDF5 (The HDF Group) before 2.2.0 lets an attacker who supplies a crafted HDF5 file corrupt heap memory in any application linked against the library, causing a crash and potentially achieving arbitrary code execution. The flaw lives in H5VM_array_fill() (src/H5VM.c) and is triggered when a dataset's unallocated/unwritten chunks are read: H5D__fill_init() derives the fill-value buffer from datatype and dataspace metadata stored in the file, and when that metadata is inconsistent with the buffer's allocated size the write overruns the buffer with attacker-controlled fill-value bytes. …

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Vulnerability AssessmentAI

Exploitation	Exploitation requires a victim to open or process an attacker-crafted HDF5 file (AV:L, UI:P) in an application linked against HDF5 before 2.2.0. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	The CVSS 4.0 base score of 8.5 (High) reflects full confidentiality, integrity, and availability impact (VC:H/VI:H/VA:H) from a heap-based buffer overflow (CWE-122), but the vector tells a more nuanced story: AV:L with UI:P means this is a FILE-PARSING flaw, not a remotely reachable network service - a victim must open or process an attacker-supplied HDF5 file in a vulnerable application. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	Full exploit scenario with step-by-step reproduction available after sign-in.
Remediation	Upgrade to HDF5 2.2.0 or later, the first release containing the fix per the advisory; the underlying change is upstream PR #6529 (https://github.com/HDFGroup/hdf5/pull/6529), which replaces the "nonexistent" chunk-layout read path with a direct H5D__fill() call, so build or vendor the patched libhdf5 rather than only patching calling applications. … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 24 hours, inventory every system, container image, and pipeline that links or bundles HDF5 - including direct C/C++/Fortran consumers as well as wrappers such as h5py, PyTables, and commercial analytics or simulation stacks - and record the exact library version in each, flagging anything below HDF5 2.2.0 as affected; in parallel, suspend automatic or scheduled ingestion of untrusted, third-party, or externally sourced HDF5 files into unisolated processes and route any parsing that must continue through a disposable, least-privilege, no-network-egress sandbox. …

Threat intelligence, references, and detailed analysis are available after sign-in.