CVE-2026-21340: 
Adobe Substance 3D Designer vulnerability analysis and mitigation

CVE-2026-21340 is an out-of-bounds read vulnerability in Adobe Substance 3D Designer that can lead to memory disclosure. It affects Substance 3D Designer versions 15.1.0 and earlier (all versions prior to 15.1.2). Exploitation requires user interaction — a victim must open a specially crafted malicious file. The vulnerability was published on February 10, 2026, with a patch released the same day. It carries a CVSS v3.1 base score of 5.5 (Medium) (Adobe Advisory).

The vulnerability is classified as CWE-125 (Out-of-bounds Read), occurring when the application reads data beyond the allocated memory buffer while processing a malicious file. An attacker crafts a specially formatted file that, when opened by a victim, triggers the out-of-bounds read and exposes contents of the application's memory. The attack vector is local, requires no privileges, but does require user interaction to open the malicious file. No public proof-of-concept or detailed technical write-up has been identified (Adobe Advisory).

Successful exploitation results in a high confidentiality impact — sensitive information stored in the application's memory can be disclosed to the attacker. There is no integrity or availability impact associated with this vulnerability. The scope is limited to the affected application, with no evidence of lateral movement potential; however, memory disclosure could expose credentials, keys, or other sensitive data processed by Substance 3D Designer (Adobe Advisory).

Adobe has released a patch addressing this vulnerability in Substance 3D Designer version 15.1.2. Users should upgrade to version 15.1.2 or later immediately. As an interim measure, users should avoid opening Substance 3D Designer files from untrusted or unknown sources. Organizations may also consider implementing application sandboxing to limit the potential impact of memory disclosure (Adobe Advisory).

The Center for Internet Security (CIS) published an advisory noting multiple vulnerabilities in Adobe products patched in February 2026, including this issue, flagging the potential for information disclosure. No notable independent researcher commentary or significant social media discussion has been identified for this specific CVE (CIS Advisory).