# CVE-2026-103840: Adobe Substance 3D Stager out-of-bounds read in file parsing

Source: https://junglewise.ai/threats/cve-2026-103840-substance3d-stager-is-affected-by-an-out-of-bounds-read  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-103840 · Severity: high · CVSS 7.8 · Published 2026-10-13

Adobe Substance 3D Stager is a 3D design and content creation tool used by professionals. Multiple out-of-bounds memory access vulnerabilities in file parsing could allow an attacker to execute arbitrary code when a victim opens a specially crafted malicious file. An attacker could gain complete control over the user's system, access sensitive data, or use the compromised computer to launch further attacks.

Technologies: [Adobe Substance 3d Stager](https://junglewise.ai/threats/technologies/substance-3d-stager). Vendors: [Adobe](https://junglewise.ai/threats/vendors/adobe).

## Quick answers

**Is CVE-2026-103840 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-103840 being exploited in the wild.

**How severe is CVE-2026-103840?** High severity, with a CVSS score of 7.8, published 13 October 2026.

**Which products and versions are affected?** Adobe Substance 3d Stager 3.1.8 and earlier.

**Is there a fix for CVE-2026-103840?** Yes: fixed in 3.1.9. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-103840 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-103840?** Check whether you run Adobe Substance 3d Stager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 3.1.9

## Technical details

The vulnerability is an out-of-bounds read (CWE-125) that occurs when parsing crafted files in Substance 3D Stager versions 3.1.8 and earlier. The attack requires local access and user interaction: a victim must open a malicious file. Exploitation allows arbitrary code execution in the context of the current user with no special privileges required.

## Affected products

- Adobe Substance 3D Stager 3.1.8 and earlier

## Timeline

- 2026-10-13: disclosed
- 2026-10-13: patched

## References

- [https://www.adobe.com/trust/security/products/substance3d-stager/apsb26-170.html](https://www.adobe.com/trust/security/products/substance3d-stager/apsb26-170.html)

## Related threats

- [Adobe Substance 3D Stager NULL pointer dereference denial-of-service](https://junglewise.ai/threats/cve-2026-103852-substance3d-stager-is-affected-by-a-null-pointer-dereference)
- [Adobe Substance 3D Stager stack-based buffer overflow](https://junglewise.ai/threats/cve-2026-103851-substance3d-stager-is-affected-by-a-stack-based-buffer-overflow)
- [Adobe Substance 3D Stager out-of-bounds read in file parsing](https://junglewise.ai/threats/cve-2026-103850-substance3d-stager-is-affected-by-an-out-of-bounds-read)
- [Adobe Substance 3D Stager use-after-free vulnerability](https://junglewise.ai/threats/cve-2026-103843-substance3d-stager-is-affected-by-a-use-after-free-vulnerability)
- [Adobe Substance 3D Stager out-of-bounds read in file parsing](https://junglewise.ai/threats/cve-2026-103842-substance3d-stager-is-affected-by-an-out-of-bounds-read)