CVE-2026-19028
HDF5 integer underflow in Fletcher32 filter leads to massive out-of-bounds read
Description
H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 through 2.3.0 computes the data length to checksum by subtracting the 4-byte trailing checksum size from the input buffer size without checking that the buffer is at least 4 bytes, allowing a size_t underflow. This allows attackers to cause a denial of service (massively out-of-bounds read and application crash in H5_checksum_fletcher32) via a crafted HDF5 file with a Fletcher32-filtered chunk smaller than 4 bytes, triggered via H5Dread, e.g. by the h5ls or h5dump tools.
INFO
Published Date :
Aug. 6, 2026, 12:16 a.m.
Last Modified :
Aug. 6, 2026, 12:16 a.m.
Remotely Exploit :
No
Source :
0253b833-3e77-4dfe-9d57-17db1a2f0a74
Affected Products
The following products are affected by CVE-2026-19028
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 0253b833-3e77-4dfe-9d57-17db1a2f0a74 | ||||
| CVSS 4.0 | MEDIUM | 0253b833-3e77-4dfe-9d57-17db1a2f0a74 |
Solution
- Update HDF5 to a secure version.
- Apply relevant security patches.
- Validate input data lengths.
- Perform boundary checks on buffer sizes.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-19028.
| URL | Resource |
|---|---|
| https://github.com/HDFGroup/hdf5/issues/6488 | |
| https://github.com/HDFGroup/hdf5/issues/6490 | |
| https://github.com/HDFGroup/hdf5/pull/6497 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-19028 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-19028
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-19028 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-19028 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 0253b833-3e77-4dfe-9d57-17db1a2f0a74
Aug. 06, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'The HDF Group', 'product': 'HDF5', 'versions': [{'status': 'affected', 'version': '<=2.3.0'}], 'defaultStatus': 'unaffected'}] Added Description H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 through 2.3.0 computes the data length to checksum by subtracting the 4-byte trailing checksum size from the input buffer size without checking that the buffer is at least 4 bytes, allowing a size_t underflow. This allows attackers to cause a denial of service (massively out-of-bounds read and application crash in H5_checksum_fletcher32) via a crafted HDF5 file with a Fletcher32-filtered chunk smaller than 4 bytes, triggered via H5Dread, e.g. by the h5ls or h5dump tools. Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/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 Added CWE CWE-125 Added CWE CWE-190 Added CWE CWE-1284 Added Reference https://github.com/HDFGroup/hdf5/issues/6488 Added Reference https://github.com/HDFGroup/hdf5/issues/6490 Added Reference https://github.com/HDFGroup/hdf5/pull/6497