CVE-2026-17573Public exploit

Process crash via stale buffer pointer

Published Jul 27, 2026 · Updated Jul 27, 2026

Double free in HDF5 2.1.1 and earlier allows local users to crash h5repack by processing a crafted HDF5 file. H5D__chunk_copy() loses the current buffer pointer after reallocation, leaving cleanup to free the stale allocation twice when an oversized chunk-index size is handled. Exploitation requires a user to run h5repack on attacker-supplied input, and the bounded consequence is termination of that process.

CVSS severity5.5
Medium
EPSS probability0.12%
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

Double free in HDF5 2.1.1 and earlier allows local users to crash h5repack by processing a crafted HDF5 file. H5D__chunk_copy() loses the current buffer pointer after reallocation, leaving cleanup to free the stale allocation twice when an oversized chunk-index size is handled. Exploitation requires a user to run h5repack on attacker-supplied input, and the bounded consequence is termination of that process.

The record

CVE
CVE-2026-17573
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
The HDF Group
Product
HDF5
Classifications
CWE-415, 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

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=<= 2.1.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The HDF Group · HDF5version=<= 2.1.1

Published CVSS scores

6.7The 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:U
5.5NIST NVDCVSS: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.

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-415Double Free
T1204.002Malicious 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