Security readout for executives and security teams
Plain-English summary
A malicious file opened in Adobe After Effects could exploit an integer calculation flaw and run code with the victim’s account permissions. This could expose files, alter data, or disrupt the workstation. User interaction is required, but creative teams routinely exchange externally supplied files, making targeted delivery plausible.
Executive priority
Treat as a high-priority workstation remediation, particularly for creative teams handling external files. The impact can be severe, but exploitation needs a malicious file and user action. Establish affected inventory promptly and deploy Adobe’s approved update after confirming the fixed release in the advisory.
Technical view
CVE-2026-21321 is a CWE-190 integer overflow or wraparound affecting After Effects 25.6 and earlier. It can lead to arbitrary code execution as the current user after a victim opens a malicious file. CVSS 3.1 rates it 7.8: local attack vector, low complexity, no privileges required, user interaction required, and high confidentiality, integrity, and availability impact.
Likely exposure
Likely exposure centers on workstations running After Effects 25.6 or earlier, especially where users open project or media files from clients, contractors, shared storage, email, or downloads. Systems running later releases may be unaffected, but the supplied evidence does not clearly identify the fixed version.
Exploitation context
Exploitation requires convincing a user to open a malicious file; remote, interaction-free compromise is not described. The source bundle marks the CVE as absent from KEV and provides no other evidence of active exploitation. This does not prove exploitation is absent.
Researcher notes
The public bundle identifies integer overflow or wraparound but provides no vulnerable component, file format, memory-corruption mechanics, or detection indicators. The listed version data is not sufficient to establish an exact fixed version confidently. Researchers should use Adobe’s advisory and CVE record for authoritative version boundaries without assuming exploit availability.
Mitigation direction
- Review Adobe advisory APSB26-15 for the vendor-approved fixed release and deployment guidance.
- Update affected After Effects installations to an Adobe-designated non-affected version.
- Prioritize users who routinely receive project or media files from external parties.
- Restrict or isolate untrusted files until affected installations are remediated.
Validation and detection
- Inventory installed After Effects versions across employee and contractor workstations.
- Identify installations running version 25.6 or earlier.
- Confirm remediated versions against Adobe advisory APSB26-15.
- Verify endpoint controls can detect suspicious child processes or activity following file opening.
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-190: 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-2026-21321 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/after_effects/apsb26-15.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.
Integer Overflow or Wraparound
Integer Overflow or Wraparound represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.