How severe is CVE-2021-33794?

CVE-2021-33794 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2021-33794 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33794?

CVE-2021-33794 primarily affects Foxitsoftware Foxit Reader. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-33794?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-33794 published?

CVE-2021-33794 was published on 2021-08-11 and last updated on 2026-06-17.

CVE-2021-33794

CVE-2021-33794 is a critical-severity vulnerability in Foxitsoftware Foxit Reader with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 1% (62nd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Foxitsoftware Foxit Reader
Published: 2021-08-11
Last modified: 2026-06-17

Description

Foxit Reader before 10.1.4 and PhantomPDF before 10.1.4 allow information disclosure or an application crash after mishandling the Tab key during XFA form interaction.

Frequently asked questions

What is CVE-2021-33794?: Foxit Reader before 10.1.4 and PhantomPDF before 10.1.4 allow information disclosure or an application crash after mishandling the Tab key during XFA form interaction.
How severe is CVE-2021-33794?: CVE-2021-33794 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2021-33794 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33794?: CVE-2021-33794 primarily affects Foxitsoftware Foxit Reader. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33794?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-33794 published?: CVE-2021-33794 was published on 2021-08-11 and last updated on 2026-06-17.

References

https://www.foxitsoftware.com/support/security-bulletins.html

Affected products (2)

cpe:2.3:a:foxitsoftware:foxit_reader:*:*:*:*:*:*:*:*
cpe:2.3:a:foxitsoftware:phantompdf:*:*:*:*:*:*:*:*