CVE-2026-19026
Description
A flaw was found in HDF5. A remote attacker could craft a malicious HDF5 file that, when opened and read, would cause an application using the HDF5 library to crash. This issue stems from improper validation of input data within the N-Bit filter, leading to a denial of service (DoS) and impacting the availability of services that process these files.
Statement
A flaw was found in HDF5's N-Bit filter implementation within H5Z__filter_nbit(). When processing dataset pipelines, the function accesses elements in the cd_values array without verifying that the pointer is non-NULL or that cd_nelmts meets the minimum 5-element header requirement. A local attacker can supply a crafted HDF5 file containing an N-Bit filter pipeline with zero client-data values. Opening and reading this file using H5Dread() or utilities like h5ls and h5repack triggers a NULL pointer dereference or out-of-bounds read, causing an application crash and denial of service.
Mitigation
Do not open or process untrusted HDF5 files using applications or CLI tools (such as h5ls or h5repack) linked against vulnerable versions of the HDF5 library. Verify file sources or isolate untrusted file parsing within a restricted, sandboxed environment.
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 | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | 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:N/UI:R/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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