CVE-2026-91814: Security vulnerability: Foxit PDF Editor/Reader Fails to Detect Modifications to Signed Documents Displaying Newly Added Content

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-23 · updated 2026-10-29
Weakness: CWE-347

Description

A signature validation vulnerability exists in Foxit PDF Editor/Reader’s handling of incrementally updated PDF documents. Changes to visible document content may not invalidate the existing signature, allowing attackers to alter signed content and potentially carry out content spoofing while the document continues to appear validly signed.

Affected products

Foxit PDF Reader: through 13.2.5.63482; from 14.0.0.33046 through 14.0.7.33751; 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 2026.2.0.39747
Foxit Pdf Reader: through 2026.2.0.39747; through 2026.2.1.39815
Foxit Software Inc. Foxit PDF Editor: through Versions 2026.2; through Versions 14.0.7; through Versions 13.2.6
Foxit Software Inc. Foxit PDF Reader: through Versions 2026.2

References

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

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