CVE-2026-21302: Substance3D Modeler Information Disclosure

CVE-2026-21302 Overview

Adobe Substance3D Modeler versions 1.22.4 and earlier contain an Out-of-Bounds Read vulnerability (CWE-125) that could lead to sensitive memory exposure. This vulnerability allows an attacker to disclose sensitive information stored in memory by exploiting improper bounds checking during file processing operations. Successful exploitation requires user interaction, specifically opening a maliciously crafted file.

Critical Impact

Attackers can leverage this vulnerability to read sensitive memory contents, potentially exposing confidential data, credentials, or other information that could facilitate further attacks against affected systems.

Affected Products

• Adobe Substance3D - Modeler version 1.22.4
• Adobe Substance3D - Modeler versions prior to 1.22.4

Discovery Timeline

• January 13, 2026 - CVE-2026-21302 published to NVD
• January 13, 2026 - Last updated in NVD database

Technical Details for CVE-2026-21302

Vulnerability Analysis

This Out-of-Bounds Read vulnerability exists in Adobe Substance3D Modeler's file parsing functionality. When the application processes certain malformed input files, it fails to properly validate memory access boundaries before reading data. This allows memory reads beyond the intended buffer limits, exposing adjacent memory regions that may contain sensitive information.

The vulnerability requires local access to the target system, meaning an attacker must either have local access or convince a user to open a malicious file. The attack complexity is low once user interaction is achieved, and no privileges are required to execute the attack. The confidentiality impact is high as sensitive memory contents can be disclosed, though there is no impact on system integrity or availability.

Root Cause

The root cause of CVE-2026-21302 stems from insufficient bounds checking in the file parsing routines of Substance3D Modeler. When processing specially crafted 3D model files or project data, the application reads memory beyond the allocated buffer boundaries. This occurs because the software does not adequately validate the size or offset parameters specified in the input file against the actual allocated memory regions, allowing attackers to craft files that trigger out-of-bounds memory reads.

Attack Vector

The attack vector for this vulnerability is local, requiring user interaction. An attacker would need to craft a malicious Substance3D Modeler file and convince a victim to open it. This could be accomplished through:

• Distributing malicious 3D model files via email attachments or file sharing platforms
• Hosting malicious files on compromised or attacker-controlled websites
• Social engineering campaigns targeting 3D artists and designers who regularly work with Substance3D Modeler

When a victim opens the malicious file, the out-of-bounds read occurs during the file parsing process. The disclosed memory contents could reveal sensitive information such as authentication tokens, encryption keys, or other data present in the application's memory space. This information could then be exfiltrated to the attacker through various means, potentially facilitating additional attacks.

Detection Methods for CVE-2026-21302

Indicators of Compromise

• Unexpected crashes or abnormal behavior in Adobe Substance3D Modeler when opening project files
• Suspicious network connections initiated by the Substance3D Modeler process after opening files from untrusted sources
• Presence of unusual or unexpected 3D model files in download directories or email attachments
• Memory access violations or exception logs related to the Substance3D Modeler.exe process

Detection Strategies

• Monitor for unusual file access patterns involving Substance3D Modeler project files from untrusted locations
• Implement endpoint detection rules to identify Out-of-Bounds Read exploitation attempts targeting Adobe applications
• Deploy file integrity monitoring for known malicious file signatures associated with this vulnerability
• Review email gateway logs for suspicious attachments with Substance3D Modeler file extensions

Monitoring Recommendations

• Enable detailed application logging for Adobe Substance3D Modeler to capture file parsing operations
• Configure SIEM rules to alert on memory access violations or exceptions from the Substance3D Modeler process
• Monitor user download activity for files with 3D modeling extensions from untrusted sources
• Implement behavioral analysis to detect unusual memory access patterns in creative applications

How to Mitigate CVE-2026-21302

Immediate Actions Required

• Update Adobe Substance3D Modeler to the latest patched version as referenced in APSB26-08
• Educate users about the risks of opening 3D model files from untrusted or unknown sources
• Implement application whitelisting to control which files can be opened by Substance3D Modeler
• Review and restrict inbound email attachments containing 3D modeling file formats

Patch Information

Adobe has released a security update addressing this vulnerability. Users should consult the Adobe Security Advisory APSB26-08 for detailed patch information and download the latest version of Substance3D Modeler. Organizations using this software should prioritize deployment of this update, particularly in environments where users regularly work with files from external sources.

Workarounds

• Restrict Substance3D Modeler to opening files only from trusted and verified sources until the patch is applied
• Implement network segmentation to isolate systems running vulnerable versions of the software
• Configure email filters to quarantine attachments with Substance3D Modeler file extensions for manual review
• Consider running the application in a sandboxed environment when working with files from external sources