CVE-2026-51290 in SQLite
Summary
by MITRE • 07/30/2026
SQLite 3.41 has a use-after-free vulnerability in the shared cache lock management logic of the btree module. The program frees a BtLock structure without removing the node from the linked list. Subsequent linked list traversal accesses the released memory, which can lead to denial of service and sensitive memory information disclosure.
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Analysis
by VulDB Data Team • 07/30/2026
The vulnerability under discussion represents a critical use-after-free condition within SQLite version 3.41 that specifically impacts the shared cache lock management subsystem located in the btree module. This flaw arises from improper memory management practices during the handling of BtLock structures, which are fundamental components for managing concurrent access to database files in shared cache scenarios. The issue manifests when the system frees a BtLock structure but fails to properly remove the corresponding node from an active linked list data structure, creating a dangerous scenario where freed memory remains referenced by subsequent operations.
The technical exploitation of this vulnerability occurs through the traversal of linked lists that contain references to previously freed BtLock structures. When the system attempts to access these memory locations during normal operation, it encounters deallocated memory regions that may have been overwritten or repurposed by other processes. This memory access pattern can result in undefined behavior including segmentation faults that cause denial of service conditions, where legitimate database operations fail and the application terminates unexpectedly. Additionally, the dangling pointer references may expose sensitive information from previously freed memory regions, potentially revealing database content, internal structures, or cryptographic keys that were stored in the freed memory locations.
The operational impact of this vulnerability extends beyond simple service disruption to encompass potential data exposure risks within database environments that utilize shared cache functionality. Attackers who can trigger the specific conditions leading to this use-after-free scenario may exploit it to cause system instability through denial of service attacks or potentially extract confidential information from memory dumps. The vulnerability affects systems running SQLite 3.41 where multiple processes access the same database file through shared cache mechanisms, making it particularly relevant in multi-user database environments, web applications, and embedded systems that rely on SQLite for data persistence.
Security mitigations for this vulnerability require immediate patching of affected SQLite installations to version 3.42.0 or later, which contains the necessary fixes for proper memory management during BtLock structure deallocation. System administrators should also implement monitoring solutions to detect anomalous database behavior patterns that might indicate exploitation attempts, including unexpected process terminations or unusual memory access patterns. The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software development practices, and represents a clear violation of proper memory management protocols. From an attacker's perspective, this flaw maps to ATT&CK technique T1059.007 for denial of service operations and potentially T1005 for data discovery through memory exposure, making it a significant concern for database security posture management across enterprise environments.