CVE-2026-19023: HDF5 h5dump Untrusted Pointer Dereference in Binary Output of Variable-Length String Datasets

Untrusted pointer dereference in the renderbinoutput function in the h5dump tool in HDF5 before 2.1.1 allows attackers to cause a denial of service via a variable-length string dataset with more than one element dumped in binary mode, which corrupts the per-element stride calculation and causes subsequent elements to be read from a misaligned offset and dereferenced as a pointer.