Security readout for executives and security teams
Plain-English summary
A malicious Substance3D Modeler file could corrupt memory and run attacker-controlled code with the victim’s permissions. The victim must open the file, so phishing, shared assets, downloads, and third-party project files are the main concern. Successful exploitation could compromise data, alter files, or disrupt the user’s workstation.
Executive priority
Prioritize remediation for creative teams and other users who routinely exchange external 3D assets. The required file-opening action reduces immediacy compared with unauthenticated remote exploitation, but potential code execution and full user-context impact justify high-priority patching and temporary file controls.
Technical view
CVE-2026-21299 is a CWE-787 out-of-bounds write affecting Adobe Substance3D Modeler 1.22.4 and earlier. It may enable arbitrary code execution as the current user after a crafted file is opened. CVSS 3.1 is 7.8: local delivery, low complexity, no prior privileges, required user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is concentrated on endpoints running Modeler 1.22.4 or earlier, particularly where users exchange or download project files. Systems without the product are not exposed. The bundle’s structured version range is ambiguous, so confirm exact affected and corrected releases against Adobe’s advisory.
Exploitation context
Exploitation requires a victim to open a malicious file; it is not described as remotely exploitable without interaction. The supplied bundle marks this CVE as absent from KEV and provides no evidence of active exploitation. That does not prove exploitation has never occurred.
Researcher notes
The vulnerability is an out-of-bounds write with user-triggered file processing and current-user code-execution impact. No exploit mechanics, affected file format, public proof of concept, or active exploitation evidence are supplied. The narrative says 1.22.4 and earlier; the structured version entry is unclear and should be reconciled with Adobe’s advisory.
Mitigation direction
- Check Adobe’s advisory for the vendor-confirmed corrected release and update affected installations promptly.
- Until updated, prevent users from opening untrusted or unexpectedly received Modeler files.
- Apply least privilege so successful code execution has limited user-level impact.
- Use email and download controls to quarantine suspicious Modeler-related files.
Validation and detection
- Inventory Substance3D Modeler installations and identify versions 1.22.4 or earlier.
- Confirm the installed release is outside Adobe’s affected range using the vendor advisory.
- Review whether exposed users receive external, shared, or downloaded Modeler files.
- Verify endpoint protection and file-handling controls cover affected workstations.
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-2026-21299 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-modeler/apsb26-08.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.