CVE-2026-29043Public exploit

Service crash via out-of-bounds null-byte write

Published Apr 10, 2026 · Updated Apr 10, 2026

Heap-based buffer overflow in HDF5 1.14.1-2 and earlier allows attackers to crash a parser by supplying a crafted H5 file. H5T__ref_mem_setnull calls memset to write 64 null bytes past a 16-byte heap allocation while converting crafted reference data. Exploitation requires a target to parse the file with h5dump, h5stat, or another affected consumer; the published proof of concept demonstrates an abort, while code execution is unproven.

CVSS severity5.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in HDF5 1.14.1-2 and earlier allows attackers to crash a parser by supplying a crafted H5 file. H5T__ref_mem_setnull calls memset to write 64 null bytes past a 16-byte heap allocation while converting crafted reference data. Exploitation requires a target to parse the file with h5dump, h5stat, or another affected consumer; the published proof of concept demonstrates an abort, while code execution is unproven.

The record

CVE
CVE-2026-29043
Published
Apr 10, 2026
Updated
Apr 10, 2026
Vendor
The HDF Group
Product
HDF5
Classifications
CWE-122, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 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.

  1. Affected versionversion=<= 1.14.1-2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The HDF Group · HDF5version=<= 1.14.1-2

Published CVSS scores

5.5GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1204.002User Execution: Malicious File

Public exploit references

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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