How severe is CVE-2021-38563?

CVE-2021-38563 has a CVSS 3.x base score of 9.8, 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 high, and availability high.

Is CVE-2021-38563 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38563?

CVE-2021-38563 primarily affects Foxit Pdf 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-2021-38563?

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-2021-38563 published?

CVE-2021-38563 was published on 2021-08-11 and last updated on 2026-06-17.

CVE-2021-38563

CVE-2021-38563 is a critical-severity vulnerability in Foxit Pdf Reader with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-129.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-129
Affected product: Foxit Pdf Reader
Published: 2021-08-11
Last modified: 2026-06-17

Description

An issue was discovered in Foxit PDF Reader before 11.0.1 and PDF Editor before 11.0.1. It mishandles situations in which an array size (derived from a /Size entry) is smaller than the maximum indirect object number, and thus there is an attempted incorrect array access (leading to a NULL pointer dereference, or out-of-bounds read or write).

Frequently asked questions

What is CVE-2021-38563?: An issue was discovered in Foxit PDF Reader before 11.0.1 and PDF Editor before 11.0.1. It mishandles situations in which an array size (derived from a /Size entry) is smaller than the maximum indirect object number, and thus there is an attempted incorrect array access (leading to a NULL pointer dereference, or out-of-bounds read or write).
How severe is CVE-2021-38563?: CVE-2021-38563 has a CVSS 3.x base score of 9.8, 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 high, and availability high.
Is CVE-2021-38563 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38563?: CVE-2021-38563 primarily affects Foxit Pdf 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-2021-38563?: 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-2021-38563 published?: CVE-2021-38563 was published on 2021-08-11 and last updated on 2026-06-17.

References

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

Affected products (2)

cpe:2.3:a:foxit:pdf_reader:*:*:*:*:*:*:*:*
cpe:2.3:a:foxitsoftware:pdf_editor:*:*:*:*:*:*:*:*

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