CVE-2026-27220: Adobe Acrobat DC RCE Vulnerability

CVE-2026-27220 Overview

CVE-2026-27220 is a Use After Free vulnerability affecting Adobe Acrobat Reader that could allow an attacker to achieve arbitrary code execution in the context of the current user. This memory corruption flaw exists in multiple versions of Adobe's PDF reader software across both Windows and macOS platforms. Successful exploitation requires user interaction—specifically, the victim must open a maliciously crafted PDF file.

Critical Impact

This vulnerability enables attackers to execute arbitrary code with the privileges of the current user, potentially leading to complete system compromise, data theft, or installation of malware.

Affected Products

• Adobe Acrobat DC (Continuous) version 24.001.30307 and earlier
• Adobe Acrobat Reader DC (Continuous) version 24.001.30308 and earlier
• Adobe Acrobat (Classic) version 25.001.21265 and earlier

Discovery Timeline

• 2026-03-10 - CVE-2026-27220 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2026-27220

Vulnerability Analysis

This Use After Free (CWE-416) vulnerability occurs when Adobe Acrobat Reader continues to reference memory after it has been freed. When a PDF document containing specially crafted content is processed, the application may free a memory object but subsequently attempt to use that memory region. Since the freed memory could be reallocated and contain attacker-controlled data, this creates an opportunity for code execution.

The attack requires local access through a malicious file, meaning an attacker must convince a user to open a crafted PDF document. Once opened, the vulnerability can be triggered without any additional user interaction, allowing execution of arbitrary code with the same privileges as the logged-in user.

Root Cause

The vulnerability stems from improper memory management within Adobe Acrobat Reader's PDF parsing and rendering engine. When processing certain PDF objects or structures, the application fails to properly track the lifecycle of dynamically allocated memory. This results in a dangling pointer condition where code continues to operate on memory that has already been returned to the heap.

Use After Free vulnerabilities in document readers are particularly dangerous because the freed memory region can be reclaimed through heap manipulation techniques, allowing attackers to place controlled data at predictable memory locations that the application will subsequently reference.

Attack Vector

The attack vector is local, requiring an attacker to deliver a malicious PDF file to the target. Common delivery methods include:

• Email attachments with crafted PDF documents
• Drive-by downloads from compromised or malicious websites
• Distribution through file-sharing platforms
• Social engineering tactics to convince users to open malicious files

When the victim opens the malicious PDF in Adobe Acrobat Reader, the crafted content triggers the Use After Free condition. Through careful heap manipulation embedded in the PDF, an attacker can gain control of program execution flow and run arbitrary code.

The vulnerability affects systems running both Windows and macOS operating systems, making it a cross-platform threat for organizations using Adobe Acrobat Reader in heterogeneous environments.

Detection Methods for CVE-2026-27220

Indicators of Compromise

• Unexpected crashes of Adobe Acrobat Reader processes, particularly when opening PDF files from untrusted sources
• Memory access violations or exception logs related to AcroRd32.exe or Acrobat.exe processes
• Suspicious child processes spawned by Adobe Acrobat Reader applications
• PDF files with unusual embedded JavaScript or object stream structures

Detection Strategies

• Deploy endpoint detection and response (EDR) solutions to monitor for anomalous behavior from Adobe Acrobat Reader processes
• Implement file inspection capabilities to scan PDF attachments before delivery to end users
• Enable application crash reporting and analyze dumps for exploitation patterns
• Monitor for process injection or unexpected code execution originating from PDF reader processes

Monitoring Recommendations

• Enable verbose logging for Adobe Acrobat Reader to capture processing errors and exceptions
• Configure SIEM rules to alert on multiple Acrobat Reader crashes within a short timeframe
• Monitor network traffic for command and control communications following PDF file access
• Track file access patterns for recently opened PDF documents from external sources

How to Mitigate CVE-2026-27220

Immediate Actions Required

• Update Adobe Acrobat Reader to the latest patched version immediately
• Enable Protected Mode and Protected View in Adobe Acrobat Reader settings
• Implement email filtering to quarantine PDF attachments from untrusted sources
• Educate users about the risks of opening PDF files from unknown senders

Patch Information

Adobe has released security patches addressing this vulnerability. Refer to Adobe Security Advisory APSB26-26 for detailed patch information and download links. Organizations should prioritize updating to the latest versions of Adobe Acrobat DC, Adobe Acrobat Reader DC, and Adobe Acrobat Classic.

Workarounds

• Enable Protected Mode in Adobe Acrobat Reader (Edit > Preferences > Security (Enhanced) > Enable Protected Mode at startup)
• Configure Protected View for files from untrusted sources and all files
• Use alternative PDF readers for documents from untrusted sources until patching is complete
• Implement application whitelisting to prevent unauthorized code execution from PDF reader processes

# Configuration example - Enable Protected View via Registry (Windows)
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\TrustManager" /v bEnableAlwaysOutlookPreviewProtectedView /t REG_DWORD /d 1 /f
reg add "HKCU\Software\Adobe\Acrobat Reader\DC\TrustManager" /v iProtectedView /t REG_DWORD /d 2 /f