CVE-2026-19028

Summary

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.

Affected Software

VendorProductVersion RangeStatus
The HDF GroupHDF5<=2.3.0affected

Weaknesses

  • CWE-190: CWE-190 Integer overflow or wraparound
  • CWE-125: CWE-125 Out-of-bounds read
  • CWE-1284: CWE-1284 Improper validation of specified quantity in input

References