CVE-2021-21870: Foxit PDF Reader

High severity, CVSS 8.8. EPSS: 1.9% chance of exploitation in the next 30 days.

A use-after-free vulnerability exists in the JavaScript engine of Foxit Software’s PDF Reader, version 10.1.4.37651. A specially crafted PDF document can trigger the reuse of previously free memory, which can lead to arbitrary code execution. An attacker needs to trick the user into opening a malicious file or site to trigger this vulnerability if the browser plugin extension is enabled.

Affected products

• Foxit PDF Reader: version 10.1.4.37651 only

Published 2021-08-05. Last modified 2026-06-17.