CVE-2021-40326

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-08-29 · updated 2026-06-17
Weakness: CWE-347

Description

Foxit PDF Reader before 11.1 and PDF Editor before 11.1, and PhantomPDF before 10.1.6, mishandle hidden and incremental data in signed documents. An attacker can write to an arbitrary file, and display controlled contents, during signature verification.

Affected products

Foxit PDF Reader: from 11.0 before 11.1 — fixed in 11.1
Foxit Pdf Reader: from 11.0 before 11.1 — fixed in 11.1
Foxit Phantompdf: before 10.1.6 — fixed in 10.1.6

How to fix

Upgrade to a fixed version: Foxit PDF Reader 11.1; Foxit Pdf Reader 11.1; Foxit Phantompdf 10.1.6. Check the vendor advisory for mitigations.

References

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

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