CVE-2026-19028
HDF5 integer underflow in Fletcher32 filter leads to massive out-of-bounds read
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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
No guide yetNo remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.
References (3)
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