Security readout for executives and security teams
Plain-English summary
Adobe Substance 3D Designer 15.1.0 and earlier can read memory outside expected bounds when a user opens a malicious file. This could expose sensitive data from memory. It is not a remote, no-click issue; user interaction is required.
Executive priority
Treat as a targeted workstation confidentiality risk, not an internet-scale emergency. Prioritize design teams with external file workflows and confirm Adobe’s remediation guidance is applied promptly.
Technical view
CVE-2026-21340 is a CWE-125 out-of-bounds read in Adobe Substance 3D Designer. CVSS 3.1 is 5.5: local attack vector, low complexity, no privileges, required user interaction, high confidentiality impact, no integrity or availability impact.
Likely exposure
Organizations using Adobe Substance 3D Designer 15.1.0 or earlier are potentially exposed, especially teams that open files from external collaborators, marketplaces, email, or shared repositories.
Exploitation context
The provided sources do not indicate active exploitation, and the CVE is not marked KEV. Exploitation requires convincing a victim to open a malicious file in the affected application.
Researcher notes
Evidence supports memory disclosure through malicious file handling. The bundle does not provide exploit details, proof of exploitation, or a specific fixed version. Avoid assuming broader Adobe product impact beyond Substance 3D Designer.
Mitigation direction
- Review Adobe APSB26-19 for the official corrected version and update guidance.
- Prioritize updates for users who handle externally supplied Substance 3D files.
- Restrict opening untrusted project files until vendor guidance is applied.
- Educate design teams to treat unexpected or externally sourced files as suspicious.
Validation and detection
- Inventory installed Adobe Substance 3D Designer versions across workstations.
- Flag installations at version 15.1.0 or earlier.
- Confirm whether affected users open files from external or untrusted sources.
- Track remediation against Adobe APSB26-19 once reviewed.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-125: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-21340 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N1.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://helpx.adobe.com/security/products/substance3d_designer/apsb26-19.htmlCVE reference · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Read
Out-of-bounds Read represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.