# CVE-2026-91799 — Foxit PDF Editor

> As of 2026-09-23, CVE-2026-91799 is a HIGH-severity vulnerability in Foxit PDF Editor, CVSS v3.1 7.8, EPSS 0.1% (2.5th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-91799, most recently “Cisco Talos disclosure: Microsoft, Adobe, Apple, and Foxit vulnerabilities (CVE-2026-48388, CVE-2026-57256, CVE-2026-91799, CVE-2026-50475, CVE-2026-58613, CVE-2026-80093, CVE-2026-49177)”.

**Last updated:** 2026-09-23

## What is CVE-2026-91799?

A use-after-free vulnerability exists in Foxit PDF Editor/Reader’s handling of JavaScript array objects. A specially crafted PDF may cause the application to access a released object during array processing, potentially resulting in application crashes or arbitrary code execution.

The record classifies CVE-2026-91799 under weakness class [CWE-416](https://intel.threadlinqs.com/cwe/CWE-416). Its CVSS v3 base vector states that the flaw requires local access to the host, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 2 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 17 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.8 — HIGH (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 2.5% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-09-23

## Is CVE-2026-91799 being exploited?

Weaponised exploit code for CVE-2026-91799 is publicly available. 1 public proof-of-concept repository is tracked for this identifier. It currently carries a trending score of 39 in the Threadlinqs vulnerability feed.

- [trickest/cve](https://github.com/trickest/cve/blob/main/2026/CVE-2026-91799.md) (trickest)

## Affected products and versions

- **Foxit Software Inc.**: Foxit PDF Editor, Foxit PDF Reader

## How to fix CVE-2026-91799

Vendor advisory: [https://www.foxit.com/support/security-bulletins.html](https://www.foxit.com/support/security-bulletins.html). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2026-91799

1 tracked threat in the Threadlinqs corpus references CVE-2026-91799, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Cisco Talos disclosure: Microsoft, Adobe, Apple, and Foxit vulnerabilities (CVE-2026-48388, CVE-2026-57256, CVE-2026-91799, CVE-2026-50475, CVE-2026-58613, CVE-2026-80093, CVE-2026-49177)](https://intel.threadlinqs.com/threat/TL-2026-3011) — HIGH · 2026-10-07

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-10-10. This product uses the NVD API but is not endorsed or certified by the NVD.

**Other references**

- [foxit.com](https://www.foxit.com/support/security-bulletins.html)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-91799
Full detection coverage and IOCs for threats exploiting CVE-2026-91799 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp