CVE-2026-21347: Adobe Bridge RCE Vulnerability

CVE-2026-21347 Overview

CVE-2026-21347 is an integer overflow vulnerability [CWE-190] affecting Adobe Bridge versions 15.1.3, 16.0.1, and earlier. Successful exploitation allows arbitrary code execution in the context of the current user. The vulnerability requires user interaction: a victim must open a malicious file crafted by the attacker. Adobe published the issue on February 10, 2026, and assigned a CVSS 3.1 base score of 7.8. The vulnerability is tracked in Adobe Security Advisory APSB26-21 and impacts Bridge installations on both Microsoft Windows and Apple macOS platforms.

Critical Impact

An attacker who convinces a user to open a malicious file can execute arbitrary code with the privileges of the current user, leading to full compromise of the user session.

Affected Products

• Adobe Bridge 15.1.3 and earlier
• Adobe Bridge 16.0.1 and earlier
• Adobe Bridge on Microsoft Windows and Apple macOS

Discovery Timeline

• 2026-02-10 - CVE-2026-21347 published to NVD
• 2026-02-11 - Last updated in NVD database

Technical Details for CVE-2026-21347

Vulnerability Analysis

The vulnerability is classified as an Integer Overflow or Wraparound [CWE-190] in Adobe Bridge file parsing logic. When Bridge processes a maliciously crafted file, an arithmetic operation on size or length values exceeds the maximum representable integer value. The result wraps to a smaller value than expected, leading to undersized memory allocations or incorrect boundary checks. Subsequent read or write operations using the original, larger size corrupt adjacent memory regions. An attacker who controls the corrupted memory can redirect execution flow to attacker-supplied code.

Exploitation occurs entirely within the local user context. The attack vector is local and requires user interaction, since the victim must open the malicious file in Adobe Bridge. No elevated privileges are required to trigger the flaw, and successful exploitation grants code execution at the privilege level of the user running Bridge.

Root Cause

The root cause is improper validation of integer values used in memory allocation or buffer indexing calculations within Adobe Bridge file parsers. Adobe has not publicly disclosed the specific file format or parser component affected. Consult the Adobe Security Advisory APSB26-21 for vendor-supplied technical context.

Attack Vector

The attacker delivers a malicious file to the target through email, file sharing, or compromised websites. The victim opens the file in a vulnerable Adobe Bridge version, triggering the integer overflow during parsing. Execution then transfers to attacker-controlled code in the user's session. No verified public proof-of-concept is available at the time of publication.

No verified public exploit code is available for CVE-2026-21347.
Refer to Adobe Security Advisory APSB26-21 for vendor details.

Detection Methods for CVE-2026-21347

Indicators of Compromise

• Unexpected child processes spawned by Bridge.exe on Windows or Adobe Bridge on macOS, such as command shells, scripting hosts, or rundll32
• Adobe Bridge crashes or access violations recorded in Windows Event Log or macOS crash reports immediately after opening a file
• Suspicious files written to user-writable paths shortly after Bridge launches a document

Detection Strategies

• Monitor process lineage for Adobe Bridge spawning interpreters (powershell.exe, cmd.exe, wscript.exe, osascript) or network utilities
• Alert on Adobe Bridge process crashes that coincide with file-open events from untrusted directories such as Downloads or email attachment caches
• Hunt for outbound network connections initiated by the Bridge process, which are atypical for a media management application

Monitoring Recommendations

• Collect endpoint telemetry covering process creation, image loads, and file writes for the Adobe Bridge process across Windows and macOS endpoints
• Inventory installed Adobe Bridge versions and flag systems running 15.1.3, 16.0.1, or earlier builds
• Correlate user file-open activity in Bridge with subsequent privilege-bounded code execution events

How to Mitigate CVE-2026-21347

Immediate Actions Required

• Apply the Adobe Bridge security updates referenced in Adobe Security Advisory APSB26-21 to all affected Windows and macOS endpoints
• Restrict opening of Bridge-supported file formats received from untrusted sources until patching is complete
• Communicate the user-interaction requirement to end users and reinforce caution with unsolicited file attachments

Patch Information

Adobe has released fixed versions of Adobe Bridge addressing CVE-2026-21347. Refer to Adobe Security Advisory APSB26-21 for the specific patched build numbers and download locations for Windows and macOS.

Workarounds

• Block delivery of Bridge-associated file types at email and web gateways for users who do not require them
• Use application allowlisting to prevent unauthorized child processes from being spawned by Bridge.exe
• Run Adobe Bridge under a least-privilege user account to limit the impact of arbitrary code execution

# Example: enumerate installed Adobe Bridge version on Windows (PowerShell)
Get-ItemProperty "HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\*" |
  Where-Object { $_.DisplayName -like "Adobe Bridge*" } |
  Select-Object DisplayName, DisplayVersion