CVE-2026-29043 HDFGroup CVE debrief

Who should care

Defenders responsible for systems that use HDF5 should assess exposure and prioritize verifying and updating HDF5 to a version that addresses this vulnerability. This includes operators, platform administrators, vulnerability management teams, and security teams who need to review the vulnerability and its potential impact on their systems. They should also monitor for potential exploitation attempts and review compensating controls for exposed systems.

Why it matters

CVE-2026-29043 is a denial-of-service vulnerability in HDF5 that can be triggered by an attacker controlling an h5 file parsed by HDF5, potentially leading to further issues such as remote code execution. Defenders should prioritize verifying and updating HDF5 to a version that addresses this vulnerability, and assess exposure in systems that use HDF5.

• Denial-of-service condition due to heap buffer overflow
• Potential for remote code execution depending on exploitability

Technical summary

The H5T__ref_mem_setnull method in HDF5 is vulnerable to a write-based heap buffer overflow condition, which can be triggered by an attacker controlling an h5 file parsed by HDF5. This vulnerability 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. The vulnerability affects HDF5 versions 1.14.1-2 and earlier. Defenders should prioritize verifying and updating HDF5 to a version that addresses this vulnerability.

Defensive priority

Defenders should prioritize verifying and updating HDF5 to a version that addresses this vulnerability, and assess exposure in systems that use HDF5.

Recommended defensive actions

• Verify and update HDF5 to a version that addresses this vulnerability
• Assess exposure in systems that use HDF5
• Monitor for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD vulnerability detail page provide information on the vulnerability, including its description, CVSS score, and affected versions. The vulnerability is a write-based heap buffer overflow condition in the H5T__ref_mem_setnull method of HDF5, which can be triggered by an attacker controlling an h5 file parsed by HDF5. Defenders should verify and update HDF5 to a version that addresses this vulnerability, assess exposure in systems that use HDF5, and monitor for potential exploitation attempts. The CVE Program and N

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.