CVE-2026-21305
Published: 13 January 2026
Summary
CVE-2026-21305 is a high-severity Out-of-bounds Write (CWE-787) vulnerability in Adobe Substance 3D Painter. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); 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
Directly remediates the out-of-bounds write vulnerability in Substance3D Painter by requiring timely identification, reporting, and patching of the flaw.
Mitigates arbitrary code execution from the out-of-bounds write through memory protection mechanisms such as address space layout randomization and non-executable memory.
Validates and sanitizes file inputs to the application, addressing malformed files that trigger the out-of-bounds write vulnerability.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Out-of-bounds write enables client-side arbitrary code execution via malicious file opened by user (T1204.002 + T1203).
NVD Description
Substance3D - Painter versions 11.0.3 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-2026-21305 is an out-of-bounds write vulnerability (CWE-787) affecting Adobe Substance3D Painter versions 11.0.3 and earlier. This flaw can lead to arbitrary code execution in the context of the current user when processing malicious input.
The vulnerability has 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), indicating high impact with low attack complexity but requiring local access and user interaction. An attacker can exploit it by tricking a victim into opening a malicious file, resulting in code execution with the privileges of the user running the application.
Adobe Security Bulletin APSB26-10 provides details on this issue, available at https://helpx.adobe.com/security/products/substance3d_painter/apsb26-10.html. Security practitioners should consult the bulletin for patch information and mitigation guidance.
Details
- CWE(s)