CVE-2026-86093IBM Db2 11.5.0 through 11.5.9, and 12.1.0 through 12.1.5 could allow an attacker with the ability to control or impersonate a DRDA server endpoint to execute arbitrary commands on Db2 clients due to a stack-based buffer overflow that improperly copies user-controlled data into a fixed-size stack buffer without bounds checking.