CVE-2026-19028
H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 through 2.3.0 computes the data length to checksum by subtracting the 4-byte trailing checksum size from the input buffer size without checking tha…
Overview
CVE-2026-19028 is a known-severity vulnerability. It was published on August 6, 2026.
Technical description
H5Z__filter_fletcher32 in H5Zfletcher32.c in HDF5 through 2.3.0 computes the data length to checksum by subtracting the 4-byte trailing checksum size from the input buffer size without checking that the buffer is at least 4 bytes, allowing a size_t underflow. This allows attackers to cause a denial of service (massively out-of-bounds read and application crash in H5_checksum_fletcher32) via a crafted HDF5 file with a Fletcher32-filtered chunk smaller than 4 bytes, triggered via H5Dread, e.g. by the h5ls or h5dump tools.
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
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Frequently asked questions
What is CVE-2026-19028?
CVE-2026-19028 is a known-severity vulnerability. It was published on August 6, 2026.
How severe is CVE-2026-19028?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2026-19028?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-19028?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-19028 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.