CVE-2026-5939: UAF in Foxit PDF Editor/Reader via XFA calculate event

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-27 · updated 2026-10-26
Weakness: CWE-416

Description

A crafted XFA PDF can trigger a use-after-free condition during calculate event processing, causing the application to crash and resulting in an arbitrary code execution.

Affected products

Foxit PDF Reader: from 14.0.0 before 14.0.4; from 2023.0.0 before 2026.1.1 — fixed in 14.0.4, 2026.1.1
Foxit Pdf Reader: before 2026.1.1 — fixed in 2026.1.1

How to fix

Upgrade to a fixed version: Foxit PDF Reader 14.0.4, 2026.1.1; Foxit Pdf Reader 2026.1.1. Check the vendor advisory for mitigations.

References

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

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