---
title: "CVE-2026-91804: Foxit PDF Editor/Reader - Out of Bounds Write"
description: "Foxit PDF Editor/Reader contains a heap-based out-of-bounds write caused by insufficient validation of Circle annotation appearance geometry in rendering malformed Cloudy appearance streams, letting attackers cause memory corruption and crashes, exploit requires crafted PDF file."
url: https://panop.io/threat-heartbeat/CVE-2026-91804/
---

# CVE-2026-91804 Foxit PDF Editor/Reader - Out of Bounds Write

Foxit PDF Editor/Reader contains a heap-based out-of-bounds write caused by insufficient validation of Circle annotation appearance geometry in rendering malformed Cloudy appearance streams, letting attackers cause memory corruption and crashes, exploit requires crafted PDF file.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.12% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-91804)

## Details

Type

Out of Bounds Write

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Published

23 September 2026

Updated

15 October 2026

Weakness

[CWE-787](https://cwe.mitre.org/data/definitions/787.html)

## Vendor fix

Update to the latest version of Foxit PDF Editor/Reader.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-91804](https://nvd.nist.gov/vuln/detail/CVE-2026-91804)
- [https://www.foxit.com/support/security-bulletins.html](https://www.foxit.com/support/security-bulletins.html)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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