CVE-2026-18097: 
IBM Db2 vulnerability analysis and mitigation

CVE-2026-18097 is a credential disclosure vulnerability in IBM Db2 caused by the logging of plaintext passwords in trace files. It affects IBM Db2 versions 11.5.0 through 11.5.9 and 12.1.0 through 12.1.5 for Linux, UNIX, and Windows, including DB2 Connect Server. The vulnerability was published on August 12, 2026, and assigned a CVSS v3.1 base score of 5.5 (Medium) by IBM (GitHub Advisory, IBM Advisory).

The root cause is classified as CWE-532 (Insertion of Sensitive Information into Log File): IBM Db2 writes plaintext database passwords into trace files during diagnostic or debugging operations. A local attacker with low-privilege access to the system can read these trace files to recover credentials. No special configuration or elevated privileges are required beyond basic local user access, and no user interaction is needed to trigger the logging behavior (GitHub Advisory, IBM Advisory).

Successful exploitation results in a high confidentiality impact — a local attacker can recover plaintext database passwords from trace files, potentially enabling unauthorized access to the Db2 database and any data it contains. There is no direct integrity or availability impact from this vulnerability itself, but compromised credentials could facilitate further lateral movement or privilege escalation within the environment (GitHub Advisory, IBM Advisory).

There is no known public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time (Feedly). The EPSS score is 0.0, indicating a very low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires local access with at least low-privilege credentials, limiting the attack surface to insiders or attackers who have already achieved initial access.

1. Gain local access: Obtain a low-privilege local user account on the system running IBM Db2 (e.g., via phishing, credential reuse, or insider access).
2. Locate trace files: Identify the Db2 trace file directory, typically configured via the db2diag.log path or the DIAGPATH database manager configuration parameter (e.g., /home/db2inst1/sqllib/db2dump/ on Linux).
3. Read trace files: Open or search trace files for plaintext password strings using standard tools (e.g., grep -i password /path/to/trace/*.trc).
4. Extract credentials: Recover plaintext database passwords from the trace output.
5. Leverage credentials: Use the recovered passwords to authenticate to the Db2 database or other systems where credentials may be reused (IBM Advisory).

• File System: Unexpected access or reads of Db2 trace files (e.g., files in the DIAGPATH directory such as *.trc or db2diag.log) by non-DBA local user accounts.
• Logs: OS-level audit logs (e.g., Linux auditd) showing low-privilege users opening or copying Db2 trace files; Db2 audit logs recording unusual authentication attempts using credentials that may have been extracted from trace files.
• Process: Unexpected use of tools such as grep, strings, or cat against Db2 diagnostic directories by non-administrative users.

IBM has released patches addressing this vulnerability; users should upgrade IBM Db2 to a version beyond 11.5.9 (for the 11.5.x line) or beyond 12.1.5 (for the 12.1.x line) (IBM Advisory). As an interim workaround, restrict file system permissions on Db2 trace file directories so that only authorized database administrators can read them. Additionally, consider disabling verbose trace logging in production environments where it is not required, and rotate any database passwords that may have been exposed in existing trace files.

Heise (a German technology news outlet) covered the vulnerability, noting that the flaw allows plaintext passwords to be viewed in IBM Db2 trace files (Heise). The vulnerability was also catalogued by AusCERT and tracked by VulDB and Offseq Radar, reflecting standard community monitoring activity. No notable researcher commentary or significant social media discussion has been observed beyond routine aggregation.