CVE-2026-21306
Published: 13 January 2026
Summary
CVE-2026-21306 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Adobe Substance 3D Sampler. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Malicious File (T1204.002); ranked at the 12.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Requires identification, reporting, and timely correction of flaws like the out-of-bounds write vulnerability in Substance3D Sampler versions 5.1.0 and earlier to prevent arbitrary code execution.
Implements memory protection safeguards such as DEP and ASLR that directly mitigate exploitation of out-of-bounds write vulnerabilities leading to code execution.
Prohibits or restricts installation of vulnerable user-installed software like affected Substance3D Sampler versions, preventing deployment of exploitable components.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Out-of-bounds write in file parser enables RCE upon opening a crafted local file, directly mapping to user execution of a malicious file.
NVD Description
Substance3D - Sampler versions 5.1.0 and earlier are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must…
more
open a malicious file.
Deeper analysisAI
CVE-2026-21306 is an out-of-bounds write vulnerability (CWE-787) affecting Adobe Substance3D Sampler versions 5.1.0 and earlier. The flaw occurs when processing malicious files, potentially leading to arbitrary code execution in the context of the current user.
With a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), the vulnerability requires local access and user interaction, such as opening a specially crafted file. An unprivileged attacker can exploit it by tricking a victim into loading the malicious file, achieving high-impact confidentiality, integrity, and availability violations through code execution under the user's privileges.
Adobe Security Bulletin APSB26-11, available at https://helpx.adobe.com/security/products/substance3d-sampler/apsb26-11.html, details the issue and provides patches for mitigation in affected Substance3D Sampler versions.
Details
- CWE(s)