Cyber Resilience

CVE-2026-26200

Memory Safety in Hdfgroup Hdf5 ≤ 1.14.4.2

Public PoCMemory Safety
Published
19 February 2026
Modified
15 July 2026
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0036 28th percentile
Risk Priority 56 floored blend · peak EPSS

Summary

CVE-2026-26200 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Hdfgroup Hdf5. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 28th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-26200 is a write-based heap buffer overflow vulnerability (CWE-122, CWE-787) in the HDF5 data management software. Versions of HDF5 prior to 1.14.4-2 are affected when parsing malicious .h5 files, allowing an attacker with control over such a file to trigger the overflow condition.

An attacker can exploit this vulnerability locally by tricking a user into opening a specially crafted .h5 file with an affected HDF5 parser. This requires no privileges (PR:N) but user interaction (UI:R) and local access (AV:L) with low attack complexity (AC:L). Successful exploitation leads to denial-of-service, with potential for remote code execution depending on heap overflow exploitability against modern operating systems.

The GitHub Security Advisory (GHSA-5p2m-j456-9mr2) from the HDF Group confirms that upgrading to version 1.14.4-2 resolves the issue.

Real-world exploitability for remote code execution remains unknown.

EU & UK References

Vulnerability Data

HDF5 is software for managing data. Prior to version 1.14.4-2, an attacker who can control an `h5` file parsed by HDF5 can trigger a write-based heap buffer overflow condition. This can lead to a denial-of-service condition, and potentially further issues…

more

such as remote code execution depending on the practical exploitability of the heap overflow against modern operating systems. Real-world exploitability of this issue in terms of remote-code execution is currently unknown. Version 1.14.4-2 fixes the issue.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-2309Same product: Hdfgroup Hdf5
CVE-2025-2915Same product: Hdfgroup Hdf5
CVE-2025-2912Same product: Hdfgroup Hdf5
CVE-2025-2308Same product: Hdfgroup Hdf5
CVE-2025-2310Same product: Hdfgroup Hdf5
CVE-2025-6516Same product: Hdfgroup Hdf5
CVE-2025-2153Same product: Hdfgroup Hdf5
CVE-2025-2914Same product: Hdfgroup Hdf5
CVE-2025-2923Same product: Hdfgroup Hdf5
CVE-2025-2924Same product: Hdfgroup Hdf5

Affected Assets

hdfgroup
hdf5
≤ 1.14.4.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (including fuzzing and memory-error detectors) can discover heap overflows after they have been coded.

Input validation enforces bounds checking on data written to heap buffers, directly stopping the overflow condition from being introduced.

Requiring documented secure-development standards and tools can mandate bounds-checked coding practices that avoid the weakness.

Security engineering principles require use of memory-safe constructs and bounds-checked allocation routines that avoid introducing heap overflows.

Memory-protection mechanisms limit the ability of a heap overflow to execute attacker-controlled code or corrupt adjacent structures.

Flaw-remediation processes that include vulnerability scanning or static analysis will surface buffer-size errors.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 full match
prevents

Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Timely patching removes known heap-overflow instances after they exist.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

degrades

Secure coding standards directly require correct buffer-size calculations.

finds

Security testing in development and acceptance can detect heap overflows before release.

prevents

Secure development lifecycle mandates practices that reduce the likelihood of introducing heap overflows.

prevents

Application security requirements can specify bounds-checking and safe memory APIs that mitigate heap overflows.

prevents

Secure architecture and engineering principles include memory-safety and input-validation controls that address heap overflows.

prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References