CVE-2026-11816: Keras archive extraction utilities allow path traversal and arbitrary file writes

Keras versions prior to 3.14.0 are vulnerable to a path traversal issue in the archive extraction utilities located in keras/src/utils/file_utils.py. The functions filter_safe_tarinfos() and filter_safe_zipinfos() validate archive member paths against the process current working directory (CWD) instead of the actual extraction destination. When the process runs with CWD set to /, which is common in Docker containers, CI/CD runners, and Jupyter environments, the validation boundary becomes the filesystem root, allowing traversal paths to bypass the security check. Additionally, the zip filter contains a bug that causes an AttributeError when a blocked entry is encountered, leading to incomplete extraction. Furthermore, Python 3.11 installations lack the filter="data" safety net, leaving them entirely reliant on the flawed CWD-based filter. Exploitation of this vulnerability can result in arbitrary file writes outside the intended extraction directory, enabling attackers to overwrite configuration files, inject malicious code, or corrupt machine learning datasets and pipelines.