CVE-2026-19027
HDF5 out-of-bounds heap read in N-Bit filter decompression
Description
The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 through 2.3.0 advance a read index into the compressed chunk buffer without bounding it against the buffer's actual size. This allows attackers to cause an out-of-bounds heap read, and in constrained cases disclosure of adjacent heap memory into decompressed dataset values, via a crafted HDF5 file whose N-Bit filter parameters describe more decompressed data than the stored compressed chunk actually contains, triggered via H5Dread, e.g. by the h5ls or h5repack 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-2026-19027
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 version 2.3.1 or later.
- Validate file integrity after updates.
- Avoid processing untrusted HDF5 files.
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-2026-19027.
| URL | Resource |
|---|---|
| https://github.com/HDFGroup/hdf5/issues/6489 | |
| https://github.com/HDFGroup/hdf5/issues/6492 | |
| 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-2026-19027 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-2026-19027
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-2026-19027 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-19027 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 The H5Z__nbit_decompress_one_byte, H5Z__nbit_decompress_one_nooptype, and H5Z__nbit_decompress_one_atomic functions in H5Znbit.c in HDF5 through 2.3.0 advance a read index into the compressed chunk buffer without bounding it against the buffer's actual size. This allows attackers to cause an out-of-bounds heap read, and in constrained cases disclosure of adjacent heap memory into decompressed dataset values, via a crafted HDF5 file whose N-Bit filter parameters describe more decompressed data than the stored compressed chunk actually contains, triggered via H5Dread, e.g. by the h5ls or h5repack tools. Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/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 Reference https://github.com/HDFGroup/hdf5/issues/6489 Added Reference https://github.com/HDFGroup/hdf5/issues/6492 Added Reference https://github.com/HDFGroup/hdf5/pull/6497