CVE-2026-27315: Apache Cassandra: cqlsh history sensitive information leak

Sensitive Information Leak in cqlsh in Apache Cassandra 4.0 allows access to sensitive information, like passwords, from previously executed cqlsh command via  ~/.cassandra/cqlshhistory local file access.

Users are recommended to upgrade to version 4.0.20, which fixes this issue.

-- Description: Cassandra's command-line tool, cqlsh, provides a command history feature that allows users to recall previously executed commands using the up/down arrow keys. These history records are saved in the ~/.cassandra/cqlshhistory file in the user's home directory.

However, cqlsh does not redact sensitive information when saving command history. This means that if a user executes operations involving passwords (such as logging in or creating users) within cqlsh, these passwords are permanently stored in cleartext in the history file on the disk.