CVE-2026-120689
Description
A flaw was found in HDF5. When traversing internal B-tree data structures, the library fails to properly validate child node relationships if a node is already loaded in the metadata cache. An attacker could exploit this vulnerability by enticing a user or application to open a specially crafted HDF5 file containing self-referencing tree nodes. This triggers unbounded recursion and stack exhaustion, causing the application to crash and resulting in a Denial of Service (DoS).
Statement
An uncontrolled recursion vulnerability exists within the HDF5 library's H5B__iterate_helper() function during version 1 B-tree traversal. By enticing a user or automated application to parse a specially crafted HDF5 file containing self-referencing child node pointers already loaded into the metadata cache, an attacker can bypass node level verification, causing stack exhaustion and an application crash resulting in a Denial of Service.
Mitigation
Avoid parsing HDF5 files received from untrusted or unverified sources. If processing untrusted files is mandatory, isolate the parsing workflow within a sandboxed container restricted by strict resource limits.
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: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Amplification
An infinite loop will cause unexpected consumption of resources, such as CPU cycles or memory. The software's operation may slow down, or cause a long time to respond.
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