Process crash via stale dataset conversion buffer
Published Apr 9, 2026 · Updated Apr 9, 2026
Heap use-after-free in HDF5 1.14.1-2 and earlier allows attackers to crash h5dump by supplying a crafted HDF5 file. H5D__typeinfo_term frees a dataset type-conversion buffer that H5T__conv_struct later passes to memmove while reading compound data. Exploitation requires the target to parse attacker-controlled HDF5 data; the published proof of concept demonstrates a process abort, while code execution remains unverified.
Summary
What happened
Heap use-after-free in HDF5 1.14.1-2 and earlier allows attackers to crash h5dump by supplying a crafted HDF5 file. H5D__typeinfo_term frees a dataset type-conversion buffer that H5T__conv_struct later passes to memmove while reading compound data. Exploitation requires the target to parse attacker-controlled HDF5 data; the published proof of concept demonstrates a process abort, while code execution remains unverified.
The record
- CVE
- CVE-2026-34734
- Published
- Apr 9, 2026
- Updated
- Apr 9, 2026
- Vendor
- The HDF Group
- Product
- HDF5
- Classifications
- CWE-416, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 9, 2026CVE publishedPublication date reported by the CVE source.
- Apr 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=<= 1.14.1-2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Vendor h5dump proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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