Opening a booby-trapped PDF in Adobe Acrobat or Acrobat Reader could let it run its own code on your computer. Attackers were already doing this. Adobe fixed it on April 11, 2026.
- Status
- Patched: update now
- Being attacked?
- Yes[1]
- Severity
- Critical
- Updated
Adobe says it is aware of this being used in real attacks. CISA lists it too (added Apr 13, 2026). Severity: Adobe: Critical, priority 1 (APSB26-43) First reported .
Am I affected?
You are at risk if Acrobat Reader or Acrobat is version 26.001.21367 or older (Acrobat 2024: 24.001.30356 or older).
| App | Device | Affected | Fixed in |
|---|---|---|---|
| Adobe Acrobat Reader | Windows, Mac | Acrobat Reader and Acrobat (Continuous) 26.001.21367 and earlier; Acrobat 2024 24.001.30356 and earlier | 26.001.21411 (Acrobat 2024: 24.001.30362 Windows / 24.001.30360 Mac)[1] |
How to check your version
These checks only look. They do not change anything on your computer.
Adobe Acrobat Reader on Windows
Easy way: Open Acrobat Reader > Help (or Menu > Help) > About Adobe Acrobat Reader.
Or type this in PowerShellRead-only. It only reads the version and changes nothing.
(Get-Item "$env:ProgramFiles\Adobe\Acrobat DC\Acrobat\Acrobat.exe").VersionInfo.ProductVersion
Adobe Acrobat Reader on Mac
Easy way: Open Acrobat Reader > Acrobat Reader menu > About Adobe Acrobat Reader.
Or type this in TerminalRead-only. It only reads the version and changes nothing.
mdls -name kMDItemVersion "/Applications/Adobe Acrobat Reader.app"
How to fix it
- Open Acrobat Reader.
- Click Help > Check for Updates (on some versions: Menu > Help > Check for updates).
- Install the update and restart Reader.
- Do not open PDFs from emails you did not expect.
More on each app: Is my Adobe Reader up to date?
Official links
Check before installing, and only use these official links or the app's own update button.
For AI agents
This page as data: /incidents/adobe-reader-attacked-bug-apr-2026.json. All problems: /feed.json. Use read-only checks only, and ask before installing anything.
Tracking numbers (CVE): CVE-2026-34621
Sources
- MakerAdobe: Security update available for Adobe Acrobat Reader (APSB26-43) (Apr 11, 2026)
- CISACISA: Known Exploited Vulnerabilities catalog entry for CVE-2026-34621 (added 2026-04-13) (Apr 13, 2026)
- NVDNVD: CVE-2026-34621 (Apr 11, 2026)
"Maker", "CISA", "NVD", "GitHub advisory" and "Official notice" are official sources. "Researcher" and "News" are extra context.