Keras: HDF5 links can disclose local file contents

A vulnerability in keras-team/keras versions <= 3.14.0 allows arbitrary local HDF5 file content disclosure due to improper handling of HDF5 ExternalLinks. The KerasFileEditor and keras.saving.load_weights functions bypass the safe_get_h5_group and safe_get_h5_dataset helpers, which are designed to reject ExternalLinks and SoftLinks. This results in automatic dereferencing of links to external HDF5 files, enabling attackers to disclose sensitive data from the victim's local filesystem. Specifically, KerasFileEditor extracts attributes and datasets from linked files into its internal structures, while keras.saving.load_weights loads weights from linked files into the user's model. This issue can be exploited by providing a malicious .h5, .weights.h5, or .keras file containing ExternalLinks.