CVE-2026-18096 in Db2
Summary
by MITRE • 08/12/2026
IBM Db2 12.1.5 for Linux, UNIX and Windows (includes DB2 Connect Server) could allow a local attacker to cause a denial of service due to a memory leak.
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Analysis
by VulDB Data Team • 08/12/2026
This vulnerability in IBM Db2 12.1.5 represents a critical memory management flaw that can be exploited by local attackers to induce denial of service conditions. The issue stems from improper handling of memory resources within the database server's core processes, specifically affecting the DB2 Connect Server component that facilitates connectivity between different database systems. When malicious local users execute crafted operations against the database instance, the system fails to properly release allocated memory blocks, leading to progressive memory consumption until system stability is compromised.
The technical implementation of this vulnerability involves memory allocation patterns that do not adequately account for resource cleanup during certain transaction processing sequences. Attackers can leverage this weakness by performing repeated operations that trigger the problematic code paths, causing the database server to gradually consume available system memory without proper garbage collection. This behavior manifests as increasing memory usage that eventually leads to system instability, process termination, or complete service unavailability.
From an operational perspective, this vulnerability poses significant risks to database availability and business continuity. Local attackers with valid credentials can exploit this weakness to degrade system performance or completely shut down database services, affecting all applications dependent on the affected Db2 instance. The impact extends beyond simple service interruption as memory exhaustion can cause cascading failures in related system components and potentially affect other running processes on the same host system.
The vulnerability aligns with CWE-401, which specifically addresses improper handling of memory allocation and deallocation scenarios, making it a classic example of memory leak exploitation. From an adversary tactics perspective, this weakness falls under ATT&CK technique T1499.004 for endpoint denial of service, where attackers leverage system resource exhaustion to compromise availability. The local privilege requirement reduces the attack surface complexity but still represents a significant risk in environments where multiple users have legitimate access to database servers.
Mitigation strategies should focus on immediate patch application from IBM Security Advisories which address the underlying memory management implementation issues. Organizations should also implement monitoring solutions to detect unusual memory consumption patterns and establish automated alerting for database server resource utilization. Additionally, system hardening measures including restricted local user access, proper privilege separation, and regular security assessments can help reduce the attack surface. Network segmentation and database access controls should be reviewed to ensure that only authorized personnel have local access to database servers, while regular vulnerability scanning should identify similar patterns in other database components or applications running on affected systems.