CVE-2026-91812

Elevated code execution via unvalidated update certificates

Published Sep 23, 2026 · Updated Sep 23, 2026

Improper certificate validation in Foxit PDF Reader and PDF Editor 2026.2 and earlier allows man-in-the-middle attackers to execute code. FoxitUpdater accepts a certificate presented by an update server without properly validating it, allowing a forged update response to pass the transport trust check. Exploitation requires an adjacent network position and user interaction with the update flow; a successful package substitution runs with elevated system privileges.

CVSS severity7.9
High
EPSS probability0.14%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in Foxit PDF Reader and PDF Editor 2026.2 and earlier allows man-in-the-middle attackers to execute code. FoxitUpdater accepts a certificate presented by an update server without properly validating it, allowing a forged update response to pass the transport trust check. Exploitation requires an adjacent network position and user interaction with the update flow; a successful package substitution runs with elevated system privileges.

The record

CVE
CVE-2026-91812
Published
Sep 23, 2026
Updated
Sep 23, 2026
Vendor
Foxit Software Company
Product
Foxit PDF Reader
Classifications
CWE-295, T1557
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Versions 2026.2 and earlier

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Foxit Software Company · Foxit PDF Readerversion=Versions 2026.2 and earlier
Foxit Software Company · Foxit PDF Editorversion=Versions 13.2.6 and earlier; version=Versions 14.0.7 and earlier; version=Versions 2026.2 and earlier

Published CVSS scores

7.9Foxit SoftwareCVSS:3.0/AV:A/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-295Improper Certificate Validation
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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