Security readout for executives and security teams
Plain-English summary
A malicious file opened in Adobe Bridge could exploit an integer calculation flaw and run attacker-controlled code with the victim’s user permissions. Successful exploitation could compromise data, alter files, or disrupt the workstation. The issue is high severity, but it requires a user to open the crafted file.
Executive priority
Treat this as a high-priority workstation update, especially for creative, media, marketing, and content-intake teams handling external files. It is not documented as actively exploited, so emergency incident posture is unsupported; prompt patching and temporary file-handling controls are proportionate.
Technical view
CVE-2026-21347 is a CWE-190 integer overflow or wraparound in Adobe Bridge. The supplied record identifies Bridge 15.1.3, 16.0.1, and earlier as affected. Exploitation requires local file handling and user interaction, with resulting arbitrary code execution in the current user’s context. CVSS 3.1 is 7.8.
Likely exposure
Workstations using affected Adobe Bridge releases are exposed, particularly where users inspect files received through email, downloads, shared storage, or external content workflows. Accounts with elevated privileges could increase business impact. Systems without Bridge, or running releases beyond the stated affected versions, are not identified as exposed by the supplied evidence.
Exploitation context
A victim must open a malicious file in Bridge; the vulnerability is not described as remotely exploitable without user interaction. The supplied record is not in CISA KEV, and the sources provide no evidence of active exploitation, public exploit availability, or specific indicators of compromise.
Researcher notes
The CVSS vector is AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. The record establishes code execution as the current user and mandatory user interaction. It does not provide technical root-cause detail, exploit primitives, affected file formats, telemetry signatures, or confirmed exploitation. Version applicability should be reconciled with Adobe’s bulletin.
Mitigation direction
- Update Adobe Bridge beyond 15.1.3 or 16.0.1, following Adobe’s applicable branch guidance.
- Prioritize systems processing files from external or untrusted sources.
- Until updated, restrict opening unsolicited files in Bridge.
- Avoid using privileged accounts for routine Bridge workflows.
Validation and detection
- Inventory installed Adobe Bridge versions across managed endpoints.
- Confirm no installations remain at 15.1.3, 16.0.1, or earlier.
- Verify the deployed update against Adobe security bulletin APSB26-21.
- Review endpoint alerts involving Bridge; the supplied sources provide no vulnerability-specific indicators.
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-2026-21347 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/bridge/apsb26-21.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.