CVE-2026-17574Public exploit

Application crash via unchecked variable-length type tag

Published Jul 27, 2026 · Updated Jul 27, 2026

NULL pointer dereference in HDF5 2.1.1 and earlier allows local users to crash a linked application by supplying a crafted HDF5 file. H5O__dtype_decode_helper copies the variable-length type nibble from file metadata without rejecting values other than sequence or string, so later location setup reaches an assertion or NULL dereference. The target application must read the malformed attribute; the demonstrated consequence is process termination without data disclosure or modification.

CVSS severityUnavailable
Unscored
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in HDF5 2.1.1 and earlier allows local users to crash a linked application by supplying a crafted HDF5 file. H5O__dtype_decode_helper copies the variable-length type nibble from file metadata without rejecting values other than sequence or string, so later location setup reaches an assertion or NULL dereference. The target application must read the malformed attribute; the demonstrated consequence is process termination without data disclosure or modification.

The record

CVE
CVE-2026-17574
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
The HDF Group
Product
HDF5
Classifications
CWE-617, CWE-476, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 27, 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=<= 2.1.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The HDF Group · HDF5version=<= 2.1.1

Published CVSS scores

5.2The HDF GroupCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P

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-617Reachable Assertion
CWE-476NULL Pointer Dereference
T1204.002Malicious 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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