CVE-2026-86926

Undergoing Analysis Undergoing Analysis - In Progress

Heap Buffer Overflow in FileMaker Server

Publication date: 2026-09-23

Last updated on: 2026-10-06

Assigner: Apple Inc.

Description

A heap buffer overflow vulnerability in the FileMaker Server database engine block parsing routine allowed a maliciously crafted .fmp12 database file to cause memory corruption, potentially leading to arbitrary code execution. This vulnerability is addressed in FileMaker Server version 26.0.3.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-23

Last Modified

2026-10-06

Generated

2026-10-14

AI Q&A

2026-09-23

EPSS Evaluated

2026-10-12

NVD

CVE-2026-86926

EUVD

EUVD-2026-85429

Affected Vendors & Products

Vendor	Product	Version / Range
claris	filemaker_server	to 26.0.3 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

Executive Summary

This is a heap buffer overflow vulnerability in FileMaker Server's database engine. It occurs when parsing .fmp12 files, allowing a specially crafted file to corrupt memory and potentially execute arbitrary code.

Detection Guidance

Detection of this vulnerability requires inspecting FileMaker Server versions and analyzing .fmp12 database files for malformed blocks. Check FileMaker Server version with server logs or commands like 'fmsadmin list' or 'fmsadmin version'. Examine .fmp12 files using FileMaker Pro's recovery tools or hex editors for unusual block structures.

Impact Analysis

If exploited, this vulnerability could allow an attacker to run malicious code on your system by tricking you into opening a specially crafted .fmp12 file. This could lead to data theft, system damage, or unauthorized access.

Compliance Impact

This vulnerability could lead to unauthorized access or data breaches if exploited, which may impact compliance with GDPR, HIPAA, or other regulations requiring data protection and integrity. Memory corruption risks may allow attackers to exfiltrate or manipulate sensitive data stored in FileMaker databases.

Mitigation Strategies

Update FileMaker Server to version 26.0.3 or later to address the heap buffer overflow vulnerability in the database engine block parsing routine.

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