CVE-2026-91791 Foxit PDF Editor/Reader Annotation Use-After-Free Remote Code Execution Vulnerability
Attackers can execute arbitrary code or cause crashes by tricking users into opening a malicious PDF file in Foxit PDF Editor or Reader.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-91791?
CVE-2026-91791 is a high-severity use after free vulnerability in Foxit Pdf Editor, published on 23 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
When processing a specially crafted PDF file, Foxit PDF Editor/Reader may encounter a reentrant execution condition involving JavaScript triggered by page-visibility events. This can cause the application to access a released page-view object while calculating annotation boundaries, resulting in an invalid memory read and application crash.
Weakness: CWE-416
Which versions are affected by CVE-2026-91791?
It affects 2 products.
Products include Foxit Pdf Editor, Foxit Pdf Reader.
How do I fix CVE-2026-91791?
No fix has been published for CVE-2026-91791 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-91791 being exploited?
There is no known exploitation of CVE-2026-91791 in the wild and no public exploit code.
Other vulnerabilities in Foxit Pdf Editor
Sources
Also known as GHSA-3595-pphf-q59v.