{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/hdf5/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":7.8,"id":"CVE-2026-34734"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["hdf5","heap-use-after-free","cve-2026-34734","h5dump"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eCVE-2026-34734 is a heap-use-after-free vulnerability affecting HDF5 versions 1.14.1-2 and earlier. This vulnerability resides within the \u003ccode\u003eh5dump\u003c/code\u003e helper utility, a component used for displaying the contents of HDF5 files. An attacker can exploit this flaw by crafting a malicious HDF5 file (.h5) that, when processed by a vulnerable version of \u003ccode\u003eh5dump\u003c/code\u003e, triggers the use-after-free condition. Specifically, the freed object is referenced in a \u003ccode\u003ememmove\u003c/code\u003e call originating from \u003ccode\u003eH5T__conv_struct\u003c/code\u003e. The object\u0026rsquo;s memory is initially allocated by \u003ccode\u003eH5D__typeinfo_init_phase3\u003c/code\u003e and subsequently deallocated by \u003ccode\u003eH5D__typeinfo_term\u003c/code\u003e. Successful exploitation could lead to arbitrary code execution.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker crafts a malicious HDF5 file (.h5) specifically designed to trigger the use-after-free condition.\u003c/li\u003e\n\u003cli\u003eThe victim, unknowingly, attempts to examine the contents of the malicious HDF5 file using the vulnerable \u003ccode\u003eh5dump\u003c/code\u003e utility (version 1.14.1-2 or earlier).\u003c/li\u003e\n\u003cli\u003e\u003ccode\u003eh5dump\u003c/code\u003e begins parsing the malicious HDF5 file. During this parsing, the \u003ccode\u003eH5D__typeinfo_init_phase3\u003c/code\u003e function is called, allocating memory for a data structure.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003eH5D__typeinfo_term\u003c/code\u003e function is subsequently called, prematurely freeing the memory allocated by \u003ccode\u003eH5D__typeinfo_init_phase3\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eLater in the execution, the code attempts to access the previously freed memory within the \u003ccode\u003eH5T__conv_struct\u003c/code\u003e function, specifically during a \u003ccode\u003ememmove\u003c/code\u003e operation.\u003c/li\u003e\n\u003cli\u003eThis access to freed memory triggers the heap-use-after-free vulnerability.\u003c/li\u003e\n\u003cli\u003eThe attacker can potentially control the contents of the freed memory, allowing them to overwrite critical data structures or function pointers.\u003c/li\u003e\n\u003cli\u003eBy carefully crafting the HDF5 file, the attacker can leverage the use-after-free to achieve arbitrary code execution on the system.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-34734 can lead to arbitrary code execution in the context of the user running the \u003ccode\u003eh5dump\u003c/code\u003e utility. This could allow an attacker to gain complete control over the affected system, potentially leading to data theft, system compromise, or denial of service. The vulnerability affects anyone using the HDF5 library to process potentially untrusted HDF5 files.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade HDF5 to a version later than 1.14.1-2 to patch CVE-2026-34734 (reference: CVE-2026-34734).\u003c/li\u003e\n\u003cli\u003eMonitor process execution for instances of \u003ccode\u003eh5dump\u003c/code\u003e being invoked with untrusted or potentially malicious HDF5 files to identify potential exploitation attempts (reference: Sigma rule \u0026ldquo;Detect h5dump Execution with Suspicious File Arguments\u0026rdquo;).\u003c/li\u003e\n\u003cli\u003eImplement input validation on HDF5 files before processing them with \u003ccode\u003eh5dump\u003c/code\u003e to prevent malicious files from triggering the vulnerability (reference: Sigma rule \u0026ldquo;Detect h5dump Accessing Files From Suspicious Locations\u0026rdquo;).\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-09T20:16:25Z","date_published":"2026-04-09T20:16:25Z","id":"/briefs/2026-04-hdf5-uaf/","summary":"A heap-use-after-free vulnerability (CVE-2026-34734) in HDF5 version 1.14.1-2 and earlier within the h5dump helper utility can be triggered by a malicious h5 file, leading to arbitrary code execution.","title":"HDF5 Heap Use-After-Free Vulnerability in h5dump (CVE-2026-34734)","url":"https://feed.craftedsignal.io/briefs/2026-04-hdf5-uaf/"}],"language":"en","title":"CraftedSignal Threat Feed — Hdf5","version":"https://jsonfeed.org/version/1.1"}