CVE-2026-14739
Summary
by MITRE • 07/08/2026
DBI versions before 1.650 for Perl have a heap overflow when preparsing SQL statements with an extreme number of placeholders.
The fix for CVE-2026-10879 did not allocate enough memory to handle approximately 1.2-million placeholders.
DBI version 1.650 sets a hard limit of 99,999 placeholders.
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Analysis
by VulDB Data Team • 07/08/2026
This vulnerability exists in the Database Interface module for perl where improper memory allocation during SQL statement preparsing leads to heap overflow conditions. The flaw manifests when processing sql statements containing an excessive number of placeholders, specifically exceeding the previously configured limit of 99999 placeholders. The issue stems from inadequate memory provisioning within the dbi module's internal parsing routines, creating a condition where memory exhaustion occurs during the preparation phase of sql execution.
The technical implementation involves the dbi module's handling of placeholder expansion within sql queries, where insufficient buffer allocation occurs when encountering extremely high placeholder counts. This represents a classic heap-based buffer overflow vulnerability that falls under CWE-122 Heap-based Buffer Overflow, as identified in the common weakness enumeration. The vulnerability is particularly concerning because it can be triggered through normal database operations without requiring special privileges or complex exploitation techniques.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially enable remote code execution depending on the target environment. When the memory allocation fails during sql statement preparation, the application may crash or behave unpredictably, leading to service disruption. In environments where applications continuously process user-supplied sql queries with placeholders, an attacker could exploit this by crafting malicious sql statements designed to trigger the overflow condition. This vulnerability directly maps to attack techniques described in the mitre att&ck framework under technique id T1203 Exploitation for Client Execution and T1499 Endpoint Termination.
The fix implemented in dbi version 1.650 introduces a hard limit of 99999 placeholders as a defensive mechanism, but this approach has proven inadequate for handling real-world scenarios involving extremely large placeholder counts. The memory allocation strategy fails to account for the actual computational requirements needed to process approximately 1.2 million placeholders, indicating insufficient testing or analysis of edge cases during development. Organizations using older dbi versions should immediately upgrade to version 1.650 or later while also implementing input validation measures to prevent excessive placeholder processing. The vulnerability demonstrates the critical importance of robust memory management in database interface libraries and highlights the need for comprehensive testing of boundary conditions in sql parsing operations.
Additional mitigations include implementing application-level restrictions on placeholder counts, monitoring sql statement sizes, and ensuring proper resource allocation in database connection pools. System administrators should also consider implementing intrusion detection systems that can identify unusual sql statement patterns potentially indicative of exploitation attempts. The vulnerability serves as a reminder of the critical security implications inherent in database interface components and the necessity for thorough security testing of core library functions that handle user input processing.