HDF5 through 2.2.0 contains an uncontrolled recursion vulnerability in H5B__iterate_helper() in src/H5B.c. When iterating a version 1 B-tree, the function does not verify that a child node’s level matches the expected level. That check is performed only in H5B__cache_deserialize() when a node is first loaded into the metadata cache. A crafted HDF5 file whose B-tree child pointer refers back to a node already in the cache, such as a node that points to itself, bypasses the check and causes unbounded recursion, leading to stack exhaustion and a crash. This can be triggered by calling H5Gget_info() or H5Gget_num_objs() on a group in the crafted file, which reaches H5B_iterate() through H5G__obj_info() and H5G__stab_count(). An attacker who can get a user or application to open a malicious file can cause a denial of service.

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Mon, 02 Nov 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Hdfgroup
Hdfgroup hdf5
Weaknesses CWE-665
Vendors & Products Hdfgroup
Hdfgroup hdf5

Mon, 02 Nov 2026 20:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-674
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 02 Nov 2026 19:45:00 +0000

Type Values Removed Values Added
Description HDF5 through 2.2.0 contains an uncontrolled recursion vulnerability in H5B__iterate_helper() in src/H5B.c. When iterating a version 1 B-tree, the function does not verify that a child node’s level matches the expected level. That check is performed only in H5B__cache_deserialize() when a node is first loaded into the metadata cache. A crafted HDF5 file whose B-tree child pointer refers back to a node already in the cache, such as a node that points to itself, bypasses the check and causes unbounded recursion, leading to stack exhaustion and a crash. This can be triggered by calling H5Gget_info() or H5Gget_num_objs() on a group in the crafted file, which reaches H5B_iterate() through H5G__obj_info() and H5G__stab_count(). An attacker who can get a user or application to open a malicious file can cause a denial of service.
Title Uncontrolled Recursion in HDF5 H5B__iterate_helper() via Crafted File
References
Metrics cvssV4_0

{'score': 4.3, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: HDFG

Published:

Updated: 2026-11-02T19:52:35.578Z

Reserved: 2026-11-02T19:32:16.362Z

Link: CVE-2026-120689

cve-icon Vulnrichment

Updated: 2026-11-02T19:52:31.981Z

cve-icon NVD

Status : Received

Published: 2026-11-02T20:17:41.020

Modified: 2026-11-02T20:17:41.020

Link: CVE-2026-120689

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-02T20:45:07Z

Weaknesses