CVE-2026-19023
Description
A flaw was found in HDF5. The h5dump tool, used for dumping HDF5 file contents, is vulnerable to an untrusted pointer dereference. An attacker could craft a malicious HDF5 file containing a variable-length string dataset. When this file is processed in binary output mode, it can lead to a denial of service, making the tool unavailable.
Statement
This flaw is a denial of service in the h5dump command-line tool, not in the HDF5 library used by applications. Triggering it requires a user to run h5dump in binary output mode (-b) against an attacker-supplied HDF5 file containing a crafted variable-length string dataset; the tool crashes but no other process or data is affected. Because exploitation is limited to a local, interactively-invoked tool with no confidentiality or integrity impact and no effect on running services, Red Hat rates the impact as Moderate.
Mitigation
Do not run h5dump in binary output mode (-b/--binary) on HDF5 files obtained from untrusted sources. Restricting h5dump usage to trusted input files avoids the crash.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | Required | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the untrusted pointer is used in a read operation, an attacker might be able to read sensitive portions of memory.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the untrusted pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" or larger than expected by a read or write operation, the application may terminate unexpectedly.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands; Modify Memory
If the untrusted pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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