Foxit PDF Reader Vulnerable to Remote Code Execution via AcroForm Use-After-Free

A critical use-after-free vulnerability has been identified in Foxit PDF Reader's AcroForm component, enabling remote attackers to execute arbitrary code on vulnerable systems. The vulnerability, tracked as CVE-2026-57242, carries a CVSS score of 7.8 and requires user interaction for exploitation, such as opening a malicious PDF file or visiting a compromised webpage.

The specific flaw lies within the AcroForm handling mechanism. It stems from an insufficient validation of an object's existence before performing operations on it. This oversight allows an attacker to leverage the vulnerability to execute code within the context of the current process, potentially leading to a full system compromise.

Successful exploitation of this vulnerability requires an attacker to trick a user into interacting with a specially crafted PDF document or navigating to a malicious website. Once the user opens the malicious file or visits the compromised page, the vulnerability can be triggered, leading to arbitrary code execution on the victim's machine.

Foxit has acknowledged the severity of this issue and has released an update to address the vulnerability. Users are strongly advised to update their Foxit PDF Reader installations to the latest version to mitigate the risk of exploitation. Further details on the security bulletin can be found on Foxit's official support page.

The disclosure timeline indicates that the vulnerability was initially reported to the vendor on April 30, 2026. Following coordinated efforts between the reporter and Foxit, a public advisory was released on August 24, 2026, with an update to the advisory on the same day. The vulnerability was reported by an anonymous researcher.

This vulnerability highlights the ongoing risks associated with complex document parsing components in widely used software. PDF readers, in particular, are frequent targets due to their broad user base and the inherent complexity of the PDF format, which can be exploited to hide malicious code.

While user interaction is a prerequisite for exploitation, the ease with which malicious files can be distributed via email or compromised websites makes this a significant threat. Organizations and individuals should maintain vigilance regarding PDF attachments and links from untrusted sources, even with updated software.

The patching of this vulnerability by Foxit is a crucial step in protecting users. However, the existence of such flaws underscores the importance of continuous security research and prompt vendor responses to safeguard against sophisticated cyber threats.

The advisory for this Foxit PDF Reader vulnerability (CVE-2026-57252) has been updated, indicating coordinated public release on August 24, 2026. The vulnerability, discovered by Anonymous, stems from improper handling of AcroForms, specifically the lack of object existence validation before operations, leading to arbitrary code execution in the context of the current process. A CVSS score of 7.8 has been assigned to this critical flaw.

The Zero Day Initiative advisory ZDI-26-595 details a distinct use-after-free vulnerability within Foxit PDF Reader's annotation feature, separate from the previously reported AcroForm component flaw. This new vulnerability, CVE-2026-57254, also allows for remote code execution but stems from improper handling of Annotation objects, specifically the lack of validation before object operations. While both require user interaction, this advisory highlights a different attack vector within the software.