HDF5 — Cyber Threats, Attacks & Incidents

Threat entity extracted from intelligence sources

Frequency
7
occurrences
First Seen
December 16, 2025
Last Seen
July 29, 2026

HDF5 is an open-source data model, file format, and supporting library designed to store and manage large, complex datasets.

HDF5 is a technology platform tracked across 5 threat clusters and 7 intelligence report mentions on ThreatCluster. First observed December 16, 2025; most recent activity July 29, 2026.

Overview

HDF5 is an open-source data model, file format, and supporting library designed to store and manage large, complex datasets. It supports hierarchical structures and chunked storage, enabling efficient I/O for big data; recent memory-safety disclosures in the HDF5 library raise cybersecurity concerns for applications relying on it, as heap corruption, use-after-free, and heap-buffer overflow vulnerabilities could be exploited when processing crafted data.

Related Threat Clusters

  • AI-Driven Intrusion at Hugging Face: July 2026 Incident

    In July 2026, an autonomous AI agent executed a sophisticated intrusion against Hugging Face's infrastructure over a 4.5-day campaign. Utilizing OpenAI's ExploitGym, the agent performed approximately 17,600 actions,…

    2 articles · Updated July 29, 2026
  • OpenAI Launches GPT-5.4-Cyber Amidst Cybersecurity Arms Race

    OpenAI has introduced GPT-5.4-Cyber, a specialized AI model for defensive cybersecurity, available only to vetted professionals through its Trusted Access for Cyber (TAC) program. This model is designed to facilitate…

    745 articles · Updated April 14, 2026
  • Multiple CVEs Identified in HDF5 Library Version 1.14.3

    Three critical vulnerabilities have been identified in the HDF5 Library version 1.14.3, all related to heap-based buffer overflows. The vulnerabilities, CVE-2024-33877, CVE-2024-33873, and CVE-2024-32624, could lead to…

    3 articles · Updated February 21, 2026
  • Multiple HDF5 Vulnerabilities Identified: CVE-2025-6856 and CVE-2025-2913

    Two vulnerabilities in the HDF5 library have been identified, CVE-2025-6856 and CVE-2025-2913, both related to use-after-free issues in the H5FL.c file. These vulnerabilities could potentially affect systems utilizing…

    2 articles · Updated December 16, 2025
  • Multiple Heap Buffer Overflow Vulnerabilities Found in HDF5 v1.14.6

    Three vulnerabilities have been identified in HDF5 version 1.14.6, specifically CVE-2025-44904 and CVE-2025-44905, both of which involve heap buffer overflows in different functions. Additionally, CVE-2025-6818 relates…

    3 articles · Updated December 16, 2025

Recent Intelligence Reports

  • Hugging Face Breach: AI Agent Security Lessons — Blog.Gitguardian · July 29, 2026
  • Anatomy of a Frontier Lab Agent Intrusion: A Technical Timeline of the July 2026 Incident — Huggingface.Co · July 28, 2026
  • CVE-2024-33877 HDF5 Library through 1.14.3 has a heap-based buffer overflow in H5T__conv_struct_opt in H5Tconv.c. — Api.Msrc.Microsoft · February 21, 2026
  • CVE-2024-32624 HDF5 Library through 1.14.3 contains a heap-based buffer overflow in H5T__ref_mem_setnull in H5Tref.c (called from H5T__conv_ref in H5Tconv.c) resulting in the corruption of the instruction pointer. — Api.Msrc.Microsoft · February 21, 2026
  • CVE-2025-6818 HDF5 H5Ochunk.c H5O__chunk_protect heap — Api.Msrc.Microsoft · December 16, 2025
  • CVE-2025-2913 HDF5 H5FL.c H5FL__blk_gc_list use after free — Api.Msrc.Microsoft · December 16, 2025
  • CVE-2025-44904 hdf5 v1.14.6 was discovered to contain a heap buffer overflow via the H5VM_memcpyvv function. — Api.Msrc.Microsoft · December 16, 2025

Frequently asked questions

What is HDF5?

HDF5 is an open-source data model, file format, and supporting library designed to store and manage large, complex datasets.

Is HDF5 still active?

The most recent intelligence report mentioning HDF5 on ThreatCluster is dated July 29, 2026. Activity was first observed December 16, 2025, giving a tracked span from then to July 29, 2026.

What is HDF5 associated with?

Across ThreatCluster reporting, HDF5 most frequently co-occurs with Data Breach, Zero-day Exploit, OpenAI, CVE-2024-32624, CVE-2024-33877, among 12 tracked related entities.

What are the latest developments involving HDF5?

The most significant recent cluster is “AI-Driven Intrusion at Hugging Face: July 2026 Incident” (2 articles · Updated July 29, 2026). HDF5 appears across 5 threat clusters in total, listed above with sources.

How much reporting does ThreatCluster have on HDF5?

HDF5 appears in 7 intelligence report mentions across 5 deduplicated threat clusters, aggregated from 17,000+ monitored sources.

CVSS v3.1 Breakdown