Answer in brief
CVE-2026-120689 records a Medium severity (CVSS 4.3) vulnerability in Uncontrolled Recursion in HDF5 H5B__iterate_helper() via Crafted File. The current sources do not mark it as known exploited. The current feed maps The HDF Group/HDF5 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 4.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps The HDF Group/HDF5 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| The HDF Group/HDF5generic | <2.3.0 | 2.3.0 |
Published upstream
Nov 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 2, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 2, 2026
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.
Quoted source text, attributed separately from HOL analysis.