CVE-2021-21822: A use-after-free vulnerability exists in the JavaScript engine of Foxit Software’s PDF Reader, version 10.1.3.

This month

HIGH 8.8DOWNGRADE

CVE-2021-21822 is a high-severity flaw (CVSS 8.8) affecting foxit reader. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A use-after-free vulnerability exists in the JavaScript engine of Foxit Software’s PDF Reader, version 10.1.3.37598. 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.

Why this priority

High severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.8% (top 22%)
CISA exploited list	No
Weakness	CWE-416
Published	2021-05-10
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: foxitsoftware

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-05-10 16:15 UTCPublished CVE record published
2026-06-17 03:36 UTCUpdated Record last modified

foxitsoftware foxit reader DOWNGRADE

Affected: 10.1.3.37598

Fixed in: no fixed release known

Safe to downgrade to: a release before 10.1.3.37598

1. Check installed version

apt-cache policy foxit-reader || rpm -q foxit-reader || foxit-reader --version

2. No fixed release: DOWNGRADE to a release before 10.1.3.37598 (Debian / Ubuntu)

apt-cache madison foxit-reader sudo apt install foxit-reader=<VERSION_BEFORE_10.1.3.37598> sudo apt-mark hold foxit-reader

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list foxit-reader sudo dnf downgrade foxit-reader-<VERSION_BEFORE_10.1.3.37598> sudo dnf versionlock add foxit-reader

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-21822?

foxit reader: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-21822 being exploited?

CVE-2021-21822 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-21822 affect?

CVE-2021-21822 affects foxit reader. Severity is high (CVSS 8.8). A use-after-free vulnerability exists in the JavaScript engine of Foxit Software’s PDF Reader, version 10.1.3.37598. A specially crafted PDF document can trigger the reuse of previously free memory, which can lead to arbitrary code executio

How urgent is CVE-2021-21822?

Priority 55/100. High severity; Public exploit reference

Related CVEs

CVE-2022-43310 HIGH 7.8 UPGRADE An Uncontrolled Search Path Element in Foxit Software released Foxit Reader v11.2.118.51569 allows attackers t
CVE-2021-38574 CRITICAL 9.8 UPGRADE UPGRADE An issue was discovered in Foxit Reader and PhantomPDF before 10.1.4
CVE-2021-38573 CRITICAL 9.8 UPGRADE UPGRADE An issue was discovered in Foxit Reader and PhantomPDF before 10.1.4
CVE-2021-38572 CRITICAL 9.8 UPGRADE UPGRADE An issue was discovered in Foxit Reader and PhantomPDF before 10.1.4
CVE-2021-38571 HIGH 7.8 UPGRADE UPGRADE An issue was discovered in Foxit Reader and PhantomPDF before 10.1.4

References

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