Security readout for executives and security teams
Plain-English summary
A malicious Substance 3D Designer file could corrupt memory and run code with the victim’s account permissions when opened. This creates meaningful risk for design teams receiving project files from external or untrusted sources.
Executive priority
Treat as a high-priority workstation remediation for design environments, especially those accepting external files. It is not demonstrated as an emergency internet-wide threat, but successful exploitation could compromise business data and endpoint operations.
Technical view
CVE-2026-21335 is a CWE-787 out-of-bounds write in Adobe Substance 3D Designer. It requires local file opening and user interaction, but no prior privileges. Successful exploitation could compromise confidentiality, integrity, and availability within the current user’s security context. CVSS v3.1 is 7.8.
Likely exposure
Exposure is concentrated on endpoints running affected Designer releases, particularly where users exchange files with clients, vendors, communities, or other untrusted parties. The bundle conflicts on the precise affected boundary: its description says 15.1.0 and earlier, while structured data references 15.1.2.
Exploitation context
Exploitation requires a victim to open a malicious file. The supplied sources do not establish active exploitation, and the CVE is not identified as being in KEV. No exploit availability evidence is provided.
Researcher notes
The supplied CVSS vector is AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Analysis should preserve the current-user execution boundary and required user interaction. The inconsistent affected-version data prevents a definitive cutoff; Adobe APSB26-19 should govern version validation and remediation.
Mitigation direction
- Review Adobe advisory APSB26-19 and deploy Adobe’s recommended secure release.
- Prioritize systems whose users routinely open externally supplied Designer files.
- Until updated, restrict or scrutinize untrusted Designer files and transfer sources.
- Use least-privilege user accounts to limit the impact of successful code execution.
Validation and detection
- Inventory installed Substance 3D Designer versions across managed endpoints.
- Resolve the version-boundary discrepancy against Adobe advisory APSB26-19.
- Confirm affected installations were upgraded to Adobe’s recommended secure release.
- Verify security controls flag or isolate unexpected Designer files from external sources.
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-787: 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-21335 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
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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.
SSVC decision data
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:H/A:H1.85.9adobeVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://helpx.adobe.com/security/products/substance3d_designer/apsb26-19.htmlCVE reference, adobe · 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 Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.