External risk intelligence

DBI Heap Overflow with Excessive Placeholders.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-14739

DBI is a database interface library. While it processes data that may originate from network-facing applications, the library itself is a backend component. Public internet exposure depends on whether the specific application using the library accepts and processes untrusted SQL input directly, making internet reachability possible but not inherent to the component's design.

Out-of-bounds Write

Perl Dbi

before 1.650

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability exists in a widely used database interface library that could allow attackers to overflow system memory when processing SQL statements with a very large number of placeholders. This memory overflow could potentially lead to system instability or compromise. The main concern is confirming if our systems utilize this library and are exposed to this specific processing scenario.

Database library has a memory overflow flaw.
Affects memory handling for many SQL placeholders.
Confirm relevance and assess potential exposure.

Attack Path

How an attacker could exploit the issue

An attacker could target applications that use a vulnerable version of the DBI library for Perl. By sending an SQL query with an extremely large number of placeholders, they could trigger a heap overflow. This vulnerability, if successfully triggered, could allow an attacker to remotely execute code.

No special access required.
Prepared SQL with many placeholders.
Remote code execution possible.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow an attacker to cause a denial-of-service condition by exploiting a heap overflow when preparsing SQL statements with a very large number of placeholders. This could impact the availability of applications that use the affected library and interact with databases.

Service availability.
Denial-of-service via heap overflow.
Application unavailability.

Operational Fix

Recommended remediation, mitigation, and detection steps

DBI, a Perl database interface library, may be affected by a heap overflow when processing SQL statements with an excessive number of placeholders. Ownership likely falls to application owners and platform teams who manage Perl applications and their dependencies, with coordination from security teams. The first practical step involves identifying all instances of DBI, assessing their reachability and business criticality, and then prioritizing remediation efforts based on risk.

Application and platform teams own remediation.
Verify reachability and business criticality first.
Plan remediation based on identified risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is the DBI Perl module?

DBI (Database Interface) is a standard database access module for the Perl programming language. It acts as an abstraction layer, allowing developers to write database-agnostic code to interact with various database management systems, such as PostgreSQL, MySQL, and SQLite. Because it handles the translation between Perl applications and database engines, it is a foundational component for many web applications and data processing scripts.

What does CWE-787 mean for CVE-2026-14739?

CWE-787 refers to a 'Heap-based Buffer Overflow.' This is a memory corruption weakness that occurs when a program writes more data to a specific area of memory (the heap) than that area was designed to hold. In the context of this CVE, the vulnerability happens when the DBI library attempts to process an extremely large number of SQL placeholders in a single statement, exceeding the memory allocated for that task and potentially crashing the system or allowing arbitrary code execution.

How is this DBI heap overflow triggered?

The vulnerability is triggered when the library processes a specifically crafted SQL query containing an excessive count of placeholders. It is not triggered by normal or standard SQL usage. The flaw specifically relates to how the library calculates memory needs for these parameters. If a query does not contain an unusually high volume of placeholders, the specific memory allocation failure that leads to this overflow will not occur.

Is my application at risk if it uses DBI?

Halo Surface Signal indicates this is a backend library; its risk depends on how your application uses it. If your application takes untrusted user input and passes it directly to DBI to construct SQL queries with many placeholders, it may be reachable from the network. If the library is used only in internal, non-public processes, the risk is lower. Evaluate whether your code allows external users to influence the number of placeholders processed by your database queries.

How do I address CVE-2026-14739?

Your first step is to identify all applications or scripts in your environment that utilize DBI versions earlier than 1.650. Once identified, audit these applications to see if they accept user-supplied input that could generate SQL queries with a massive number of placeholders. Prioritize updating to DBI version 1.650, which implements a strict, safe limit of 99,999 placeholders, effectively neutralizing this specific trigger path.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.