CVE-2026-120755
Integer Underflow Leads to Out-of-Bounds Read via Truncated Chunk in HDF5 Szip Filter
Description
HDF5 through 2.2.0 contains an out-of-bounds read vulnerability in H5Z__filter_szip() in src/H5Zszip.c. When decoding a szip-compressed chunk, the function subtracts the 4-byte uncompressed-length header from the chunk length without first verifying that the chunk is at least 4 bytes long. A truncated or corrupted chunk shorter than the header causes the length calculation to wrap around to a very large value, and the decompressor reads far past the end of the chunk buffer. An attacker who can get a user or application to read a dataset from a crafted HDF5 file can cause a denial of service. Only builds with szip support (libaec or the szip library) are affected.
INFO
Published Date :
Nov. 3, 2026, 4:17 p.m.
Last Modified :
Nov. 3, 2026, 9:10 p.m.
Remotely Exploit :
No
Source :
0253b833-3e77-4dfe-9d57-17db1a2f0a74
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 0253b833-3e77-4dfe-9d57-17db1a2f0a74 | ||||
| CVSS 4.0 | MEDIUM | 0253b833-3e77-4dfe-9d57-17db1a2f0a74 |
Solution
- Update HDF5 to a patched version.
- Disable SZIP compression if updating is not possible.
- Validate HDF5 file integrity before processing.
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-2026-120755.
| URL | Resource |
|---|---|
| https://github.com/HDFGroup/hdf5/pull/6585 | Issue Tracking Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-120755 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-2026-120755
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-2026-120755 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-120755 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.
-
Initial Analysis by [email protected]
Nov. 03, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:hdfgroup:hdf5:*:*:*:*:*:*:*:* versions up to (including) 2.2.0 Added Reference Type HDFG: https://github.com/HDFGroup/hdf5/pull/6585 Types: Issue Tracking, Patch -
New CVE Received by 0253b833-3e77-4dfe-9d57-17db1a2f0a74
Nov. 03, 2026
Action Type Old Value New Value Added Description HDF5 through 2.2.0 contains an out-of-bounds read vulnerability in H5Z__filter_szip() in src/H5Zszip.c. When decoding a szip-compressed chunk, the function subtracts the 4-byte uncompressed-length header from the chunk length without first verifying that the chunk is at least 4 bytes long. A truncated or corrupted chunk shorter than the header causes the length calculation to wrap around to a very large value, and the decompressor reads far past the end of the chunk buffer. An attacker who can get a user or application to read a dataset from a crafted HDF5 file can cause a denial of service. Only builds with szip support (libaec or the szip library) are affected. Added CVSS V4.0 AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/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 Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/120xxx/CVE-2026-120755.json">CVE-2026-120755</a> Added Reference https://github.com/HDFGroup/hdf5/pull/6585 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Nov. 03, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-120755', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-11-03T15:43:28.018929Z'}