CVE-2026-120758
Description
A flaw was found in HDF5. An attacker can cause a Denial of Service (DoS) by convincing a user or application to open a specially crafted HDF5 file. Due to improper handling of corrupted metadata in local heap structures, the library attempts to dereference a NULL pointer during cache operations, resulting in an application crash.
Statement
A NULL pointer dereference vulnerability was found in HDF5's H5HL_unprotect() function in src/H5HL.c. When processing a crafted file containing corrupted local heap metadata, a previously destroyed cache entry leaves internal heap pointers unlinked, causing the library to pass a NULL pointer to H5AC_unpin_entry(). An attacker who convinces a user or application to open and traverse a specially crafted HDF5 file can trigger an application crash, resulting in a denial of service.
Mitigation
Restrict file permissions to ensure HDF5 files are ingested exclusively from verified, trusted sources. Run file-parsing workloads within isolated containers or constrained sandbox environments to limit the impact of process termination.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | Required | Required | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD: 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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