CVE-2026-19026Public exploit

File-reader crash via unchecked N-Bit parameters

Published Aug 5, 2026 · Updated Aug 5, 2026

NULL pointer dereference in the N-Bit filter in The HDF Group HDF5 2.3.0 and earlier allows attackers to crash file-reading processes. H5Z__filter_nbit reads cd_values[0] through cd_values[4] before checking whether the array exists or contains the five-value filter header. A crafted HDF5 file with zero client-data values triggers the crash only when a user or application reads the affected dataset through H5Dread.

CVSS severity6.8
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

NULL pointer dereference in the N-Bit filter in The HDF Group HDF5 2.3.0 and earlier allows attackers to crash file-reading processes. H5Z__filter_nbit reads cd_values[0] through cd_values[4] before checking whether the array exists or contains the five-value filter header. A crafted HDF5 file with zero client-data values triggers the crash only when a user or application reads the affected dataset through H5Dread.

The record

CVE
CVE-2026-19026
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
The HDF Group
Product
HDF5
Classifications
CWE-1284, CWE-476, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<=2.3.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The HDF Group · HDF5version=<=2.3.0

Published CVSS scores

6.8The HDF GroupCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1284Improper Validation of Specified Quantity in Input
CWE-476NULL Pointer Dereference
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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo