What is the CVSS score of CVE-2026-26200?

CVE-2026-26200 has a CVSS 3.1 base score of 7.8 (High). CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

Is there a public PoC exploit available for CVE-2026-26200?

Yes, a public proof-of-concept exploit is available for CVE-2026-26200. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-26200?

Within 24 hours: Identify all systems running HDF5 and restrict file upload/import capabilities to trusted sources only; disable HDF5 processing of untrusted files if operationally feasible. Within 7 days: Implement network segmentation to isolate HDF5-dependent systems; deploy monitoring for suspicious file access and process execution on affected systems. Within 30 days: Monitor vendor security advisories for patch availability; evaluate migration to patched version 1.14.4-2 or later once released; conduct risk assessment to determine if systems must remain unpatched.

Hdf5 CVE-2026-26200

HIGH

Heap-based Buffer Overflow (CWE-122)

2026-02-19 security-advisories@github.com

RCE Buffer Overflow Heap Overflow Hdf5 Hdfgroup

7.8

CVSS 3.1 · Vendor: github

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Craft malicious HDF5 file
Exploit

Supply file to vulnerable application
Execution

Trigger heap buffer overflow in parser
Impact

Achieve code execution or denial-of-service

Vulnerability Assessment

Weakness	CWE CWE-122 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V15 - Secure Coding and Architecture Heap buffer bounds checking MITRE ATT&CK 1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	Attacker must provide a malicious HDF5 (.h5) file that is parsed by HDF5 library versions prior to 1.14.4-2. User interaction required to open/process the file. Affects any application using vulnerable HDF5 library versions.
Impact	CVSS 7.8 (HIGH). Attack vector: Local. Complexity: Low. Privileges required: None. User interaction: Required. Exploitable via remote/network. Public exploit/POC available.
Exploit ScenarioDerived	A remote attacker could exploit this vulnerability to a denial-of-service condition, and potentially further issues such as remote cod.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Heap buffer overflow in HDF5 versions prior to 1.14.4-2 allows attackers to trigger denial-of-service or potentially achieve code execution by crafting malicious h5 files. The vulnerability affects any system parsing untrusted HDF5 data files and has public exploit code available. A patch is not yet available, leaving affected deployments at risk.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 22:03 CVSS 7.8

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. [CVSS 7.8 HIGH]

RemediationAI

Monitor vendor advisories for a patch. Enable ASLR, DEP/NX, and stack canaries where possible.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Classified as CWE-122 (Heap-based Buffer Overflow). Affects Hdf5. 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 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 fixe

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (github) PRIMARY 7.8 HIGH

AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

SUSE HIGH

Red Hat 7.8 HIGH

Primary rating from Vendor (github).

CVSS VectorVendor: github

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Patch released

Apr 10, 2026 - 08:30 nvd

Patch available

PoC Detected

Feb 20, 2026 - 20:14 vuln.today

Public exploit code

CVE Published

Feb 19, 2026 - 20:25 nvd

HIGH 7.8

DescriptionCVE.org

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 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.

Executive ViewAI

Why It Matters

CVE-2026-26200 is a HIGH severity vulnerability affecting HDF5 data management software that allows attackers to execute arbitrary code by uploading malicious data files. Organizations using HDF5 for scientific computing, research, or data analytics are at immediate risk since no patch is currently available and public exploits exist.

Business Impact: High

Compensating Controls

Implement strict input validation and file source whitelisting for HDF5 file imports; restrict HDF5 processing to isolated, non-critical systems where possible; deploy endpoint detection and response (EDR) solutions on systems running HDF5; use file integrity monitoring on HDF5 application directories; consider application-level sandboxing; network-based controls to limit data exfiltration from affected systems. No vendor patch available—monitor HDF5 GitHub releases and security advisories for version 1.14.4-2+ availability.

Threat Intelligence Overview

EPSS Score

0.0%

Top 91% exploitable

Exploit

POC

Public exploit code exists

Data Quality

6 sources

Confidence: High

NVD

CVE.org

EPSS Vendor

GitHub

VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC Yes

EPSS 0.0%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

Poc

System Exposure· derived

Small

Automatable· derived

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +39

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Heap Overflow HIGH

A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.

Remote Code Execution CRITICAL

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

Affected Products (CPE)CVE.org

cpe:2.3:a:hdfgroup:hdf5:*:*:*:*:*:*:*:*