CVE-2026-18622: Foxit PDF Editor/Reader's signature-validation pop-up reports modified certified documents as valid

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: 2026-08-13 · updated 2026-09-10
Weakness: CWE-451

Description

Foxit PDF Editor/Reader inconsistently alerts users when signature fields are abnormally modified, including alterations to appearance, coordinates, or field duplication. This may mislead users into trusting tampered documents, since the UI cannot accurately reflect the actual integrity status of signatures.

Affected products

Foxit PDF Reader: through 13.2.5.24109; from 14.0.0.33046 through 14.0.5.33580; from 2023.1.0.15510 through 2023.3.0.23028; from 2024.1.0.23997 through 2024.4.1.27687; from 2025.1.0.27937 through 2025.3.0.35737; from 2026.1.0.36452 through 2026.1.2.36540
Foxit Pdf Reader: through 2026.1.2.36540; through 2026.1.2.70304

References

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

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