CVE-2026-27220
📋 TL;DR
A use-after-free vulnerability in Adobe Acrobat Reader allows attackers to execute arbitrary code when a user opens a malicious PDF file. This affects users running vulnerable versions of Acrobat Reader on any operating system. Successful exploitation requires user interaction but could lead to full system compromise.
💻 Affected Systems
- Adobe Acrobat Reader
📦 What is this software?
Acrobat by Adobe
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining the same privileges as the current user, potentially leading to data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Malicious PDF files delivered via phishing emails or malicious websites lead to malware installation, credential theft, or lateral movement within the network.
If Mitigated
With proper security controls, the impact is limited to the user's session without administrative privileges, and security software may detect and block the malicious file.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious file). No public exploit code is currently available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to version 24.001.30309 or 25.001.21266 or later
Vendor Advisory: https://helpx.adobe.com/security/products/acrobat/apsb26-26.html
Restart Required: Yes
Instructions:
1. Open Adobe Acrobat Reader. 2. Go to Help > Check for Updates. 3. Follow the prompts to download and install the latest version. 4. Restart the application when prompted.
🔧 Temporary Workarounds
Disable JavaScript in Adobe Reader
allPrevents JavaScript-based exploitation vectors that might be used in conjunction with this vulnerability
Edit > Preferences > JavaScript > Uncheck 'Enable Acrobat JavaScript'
Use Protected View
allOpen PDF files in Protected View mode to limit potential damage
File > Open > Select 'Protected View' option when opening files
🧯 If You Can't Patch
- Restrict PDF file opening to trusted sources only
- Implement application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check Adobe Acrobat Reader version in Help > About Adobe Acrobat ReaderCheck Version:
On Windows: wmic product where name="Adobe Acrobat Reader" get versionVerify Fix Applied:
Verify version is 24.001.30309 or higher for version 24, or 25.001.21266 or higher for version 25📡 Detection & Monitoring
Log Indicators:
- Unexpected process crashes of Acrobat Reader
- Unusual child processes spawned from Acrobat Reader
Network Indicators:
- Outbound connections from Acrobat Reader to unknown IP addresses
- DNS requests for suspicious domains after PDF opening
SIEM Query:
process_name:"AcroRd32.exe" OR process_name:"Acrobat.exe" AND (event_id:1000 OR event_id:1001) AND source_name:"Application Error"