Security Advisory Regarding Vulnerabilities in Adobe Acrobat / Reader

A critical security update for Adobe Acrobat and Adobe Acrobat Reader has been released.

This vulnerability is extremely dangerous because simply opening a specially crafted PDF file can allow an attacker to execute arbitrary programs (remote code execution) on the target computer without the user’s consent. Additionally, Adobe has confirmed that this vulnerability (CVE-2026-34621) is already being actively exploited in the wild. It is therefore considered a zero-day vulnerability and requires immediate action.

Affected Versions

• Acrobat DC / Reader DC (Continuous): version 26.001.21367 and earlier
• Acrobat 2024 (Classic 2024): version 24.001.30356 and earlier

Solution

Please update to the following latest versions:

• Acrobat DC / Reader DC: Version 26.001.21411 or later
• Acrobat 2024 (Windows): Version 24.001.30362 or later
• Acrobat 2024 (macOS): Version 24.001.30360 or later

How to Check Your Version

1. Launch Adobe Acrobat (or Reader).
2. Click the menu bar or the "hamburger menu" (three lines icon) in the upper-left corner.
3. Select Help > About Adobe Acrobat... located near the bottom of the menu.

How to Update

1. From the menu bar or the "hamburger menu" in Adobe Acrobat (or Reader), select Help > Check for Updates.
2. Follow the on-screen instructions to complete the update.

Important Notes on Updating

• 「"Programs in Use" Message: If a message stating "The program is in use" appears, please close all Acrobat and Reader windows and then click Retry.
• Multiple Updates/Reboots: The update process may take some time or require a system restart. Please run "Check for Updates" repeatedly until the message "No updates available" is displayed.。
• Creative Cloud Users: If you use the version of Acrobat included with Adobe Creative Cloud, you can update it directly via the Creative Cloud Desktop app.

Adobe：Security update available for Adobe Acrobat Reader