CVE-2026-9762: IBM Db2 RCE Vulnerability via JDBC URL

CVE-2026-9762 Overview

CVE-2026-9762 is a code injection vulnerability in IBM Db2 that allows remote code execution when the JDBC URL is under user control. The flaw affects IBM Db2 versions 11.5.0 through 11.5.9, and 12.1.0 through 12.1.4. An authenticated local attacker who can influence the JDBC connection string can trigger execution of arbitrary code within the Db2 process context. The issue is tracked under CWE-94: Improper Control of Generation of Code. IBM has published a support document with fixed versions and remediation guidance.

Critical Impact
Attacker-controlled JDBC URLs in IBM Db2 enable arbitrary code execution with high impact to confidentiality, integrity, and availability.

Affected Products

IBM Db2 versions 11.5.0 through 11.5.9
IBM Db2 versions 12.1.0 through 12.1.4
Applications embedding the Db2 JDBC driver where connection URLs are influenced by untrusted input

Discovery Timeline

2026-07-17 - CVE-2026-9762 published to NVD
2026-07-24 - Last updated in NVD database

Technical Details for CVE-2026-9762

Vulnerability Analysis

The vulnerability stems from unsafe handling of JDBC URL parameters within the IBM Db2 driver. When an application passes a JDBC URL containing attacker-influenced properties to the driver, the driver processes those properties in a way that allows code injection. The result is arbitrary code execution in the process invoking the Db2 client library. The flaw maps to [CWE-94], where generated or interpreted code paths accept unvalidated input.

Exploitation requires local access and low privileges, but no user interaction. Because the driver executes within the calling application, a successful attack inherits that application's privileges and can lead to full compromise of the host running the Db2 client.

Root Cause

The root cause is improper validation of JDBC URL components before they are parsed and acted upon by the Db2 driver. Specific properties within the connection string are interpreted as executable directives rather than opaque configuration values. When the URL originates from untrusted input, an attacker can supply properties that steer the driver into loading or invoking attacker-supplied logic.

Attack Vector

An attacker with local access and the ability to control the JDBC URL passed to a Db2 client crafts a malicious connection string. When the application initiates a database connection using that URL, the driver processes the injected properties and executes attacker-supplied code. Any application, script, or middleware that concatenates user input into a Db2 JDBC URL is a viable entry point.

Because exploitation depends on the driver behavior, no valid Db2 credentials are required if the attacker's goal is code execution rather than data access. Refer to the IBM Support Document for vendor technical details.

Detection Methods for CVE-2026-9762

Indicators of Compromise

Db2 client processes spawning unexpected child processes such as shells, scripting interpreters, or curl/wget
JDBC connection strings in application logs containing unusual driver properties, class names, or URL-encoded payloads
Outbound network connections from Db2 client hosts to unfamiliar IP addresses shortly after a database connection attempt
Application error logs referencing driver class loading or reflection failures tied to jdbc:db2: URLs

Detection Strategies

Inventory Db2 installations and confirm running versions against the affected ranges 11.5.0–11.5.9 and 12.1.0–12.1.4
Audit application source code and configuration for locations that build JDBC URLs from user input, HTTP parameters, or environment variables
Enable verbose JDBC driver logging in non-production environments to capture parsed URL properties for review
Correlate Db2 client process telemetry with process-creation and network events to surface anomalous execution chains

Monitoring Recommendations

Alert on any Db2 client JVM or application process spawning cmd.exe, powershell.exe, /bin/sh, or scripting binaries
Monitor for unusual class loading or file writes originating from processes that host the Db2 JDBC driver
Track configuration changes to files and secrets stores that contain JDBC connection strings

How to Mitigate CVE-2026-9762

Immediate Actions Required

Upgrade IBM Db2 to a fixed release as specified in the IBM Support Document
Remove any code path that allows untrusted input to influence a Db2 JDBC URL or its properties
Restrict local access to hosts running vulnerable Db2 clients and enforce least-privilege service accounts
Rotate credentials and secrets stored in JDBC configuration if compromise is suspected

Patch Information

IBM has released updated versions of Db2 addressing CVE-2026-9762. Consult the IBM Support Document for the exact fix pack levels for both the 11.5.x and 12.1.x branches. Apply patches on client and server components that ship the affected driver, and validate application connectivity after upgrade.

Workarounds

Enforce allow-lists for JDBC URL hosts, ports, and property names in application code before passing strings to DriverManager.getConnection
Construct connection URLs from validated components rather than concatenating raw user input
Store JDBC URLs in protected configuration and disallow runtime overrides from untrusted sources
Restrict filesystem and network egress from hosts running Db2 clients to limit post-exploitation impact

bash

# Configuration example: validate and pin JDBC URL components before use
# Reject any user-supplied override; construct URL from vetted values only
DB2_HOST="db2.internal.example.com"
DB2_PORT="50000"
DB2_DB="PRODDB"
JDBC_URL="jdbc:db2://${DB2_HOST}:${DB2_PORT}/${DB2_DB}"
export JDBC_URL