CVE-2026-6053 Overview
CVE-2026-6053 is a denial of service vulnerability affecting IBM Db2 versions 11.5.0 through 11.5.9 and 12.1.0 through 12.1.4. The flaw triggers when a specially crafted query executes against range partitioned tables, leading to resource exhaustion in the database engine. The weakness is categorized under [CWE-770] (Allocation of Resources Without Limits or Throttling). An authenticated local attacker with low privileges can exploit this issue to disrupt database availability without affecting confidentiality or integrity.
Critical Impact
Authenticated users can crash or stall IBM Db2 instances by submitting malformed queries against range partitioned tables, interrupting business-critical database services.
Affected Products
- IBM Db2 versions 11.5.0 through 11.5.9
- IBM Db2 versions 12.1.0 through 12.1.4
- Deployments using range partitioned tables
Discovery Timeline
- 2026-05-27 - CVE-2026-6053 published to NVD
- 2026-05-27 - Last updated in NVD database
Technical Details for CVE-2026-6053
Vulnerability Analysis
The vulnerability resides in how IBM Db2 processes queries targeting range partitioned tables. When a specially crafted query enters the query planner or execution engine, Db2 fails to enforce upper bounds on resource allocation. This leads to excessive consumption of memory or CPU, ultimately exhausting available resources and causing a denial of service condition.
The flaw does not expose data or permit modification of stored information. The integrity and confidentiality impact remain unaffected. Availability degrades severely because the database process can hang or crash, requiring administrator intervention to restore service.
Exploitation requires local access to the database with valid low-privilege credentials. No user interaction is needed beyond submitting the malicious query.
Root Cause
The root cause maps to [CWE-770], unbounded resource allocation during query processing on range partitioned tables. The query optimizer or execution engine does not adequately constrain memory, processing time, or partition enumeration when handling certain crafted inputs. Refer to the IBM Support Page for vendor-confirmed technical context.
Attack Vector
An attacker authenticated to the Db2 instance submits a crafted SQL query referencing range partitioned tables. The query forces the engine into a code path that allocates resources beyond safe limits. Because the attack vector is local and requires authentication, exposure is limited to users with existing database access, including compromised service accounts or insider threats.
No verified public exploit code is currently available for CVE-2026-6053. See the IBM Support Page for vendor remediation guidance.
Detection Methods for CVE-2026-6053
Indicators of Compromise
- Sudden spikes in Db2 memory or CPU consumption tied to query execution against range partitioned tables
- Db2 diagnostic logs (db2diag.log) showing abnormal query termination, memory allocation failures, or instance crashes
- Repeated failed query attempts from a single authenticated session targeting partitioned objects
Detection Strategies
- Monitor Db2 workload management (WLM) event monitors for queries with disproportionate resource consumption against partitioned tables
- Enable activity event monitors to capture SQL statement text and resource metrics for forensic correlation
- Correlate authentication logs with query execution telemetry to identify anomalous user behavior
Monitoring Recommendations
- Establish baselines for normal query execution times and memory usage on range partitioned tables
- Forward Db2 audit and diagnostic logs to a centralized SIEM for anomaly detection and alerting
- Alert on instance restarts, db2sysc process terminations, or unplanned failover events
How to Mitigate CVE-2026-6053
Immediate Actions Required
- Apply the IBM-provided fix as documented on the IBM Support Page
- Inventory all Db2 instances running affected versions 11.5.0 through 11.5.9 and 12.1.0 through 12.1.4
- Restrict database access to least-privilege accounts and review users with query execution rights on partitioned tables
Patch Information
IBM has published remediation guidance for affected Db2 releases. Administrators should consult the IBM Support Page for fix pack details and upgrade paths covering Db2 11.5 and 12.1 branches.
Workarounds
- Apply Db2 workload management thresholds to cap query memory and execution time on range partitioned tables
- Revoke unnecessary query privileges from non-administrative accounts pending patch deployment
- Audit and restrict ad-hoc query access against partitioned tables until the fix is applied
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
