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