Executive brief
IBM Db2 is a widely-used enterprise database system. The vulnerability allows an attacker who can intercept or control the database server connection to execute arbitrary code on database clients, potentially leading to data theft or system compromise. This requires network access to the server endpoint but does not require user authentication to the database itself.
Technical details
A stack-based buffer overflow (CWE-121) exists in IBM Db2 versions 11.5.0–11.5.9 and 12.1.0–12.1.5 in the DRDA (Distributed Relational Database Architecture) client protocol handler. The vulnerability stems from improper bounds checking when copying user-controlled data from a DRDA server response into a fixed-size stack buffer. An attacker with the ability to control or impersonate a DRDA server endpoint can craft malicious protocol messages to overflow the buffer and execute arbitrary commands on the Db2 client. The attack vector is network-based and requires the ability to intercept or control the server endpoint; no client-side user interaction is required. IBM has released security updates for supported versions (V11.5.9 and V12.1.4/V12.1.5) available through Fix Central.
Affected products
- IBM Db2 11.5.0 through 11.5.9, 12.1.0 through 12.1.5
Timeline
- 2026-09-10: disclosed