A heap-buffer-overflow vulnerability exists in the H5SM_delete function of the hdf5 library. This issue was reported by OSS-Fuzz and involves a read overflow of 4 bytes in heap memory during message deletion operations. The affected versions include 1.14.1, 2.0.0, 2.1.0-pre1test, 2.1.0, 2.1.1, 2.2.0-rc1, and 2.2.0. No public exploits or CVSS score are currently available.