CVE-2026-57258: Foxit PDF Editor Buffer Overflow Flaw

CVE-2026-57258 Overview

CVE-2026-57258 is an out-of-bounds read vulnerability [CWE-125] affecting Foxit PDF Editor and Foxit PDF Reader on Microsoft Windows and Apple macOS. The flaw resides in the PRC (Product Representation Compact) file header parsing logic. The parser trusts constructed file structure description information and assumes the underlying array contains elements before reading them. An attacker who convinces a user to open a crafted PDF containing a malicious PRC stream can trigger out-of-bounds memory reads. Successful exploitation causes application crashes and may expose adjacent process memory contents.

Critical Impact
Local exploitation requires user interaction to open a crafted PDF file, resulting in application denial of service and potential low-level information disclosure.

Affected Products

Foxit PDF Editor (Windows and macOS)
Foxit PDF Reader (Windows and macOS)
Microsoft Windows and Apple macOS host platforms

Discovery Timeline

2026-07-08 - CVE-2026-57258 published to NVD
2026-07-09 - Last updated in NVD database

Technical Details for CVE-2026-57258

Vulnerability Analysis

The vulnerability exists in how Foxit PDF applications parse embedded PRC 3D data streams. PRC is a format used to embed 3D CAD geometry inside PDF documents. During header parsing, the code path constructs an internal description of the file structure based on values read from the untrusted document. The parser then dereferences array indices without validating that the backing array actually contains the expected elements.

When a crafted PRC header advertises entries that do not exist, the parser reads beyond the allocated buffer. This produces an out-of-bounds read on process memory, which typically triggers an access violation and terminates the application. Depending on heap layout, adjacent memory contents may be processed as valid PRC data before the crash occurs.

Root Cause

The root cause is missing bounds validation between the file's self-described structure and the actual allocated array size. The parser trusts attacker-controlled length or index metadata from the PRC header. It performs element reads without verifying the array capacity, which corresponds to CWE-125 (Out-of-Bounds Read).

Attack Vector

Exploitation requires local delivery of a malicious PDF and user interaction to open the file in a vulnerable Foxit product. The attack does not require authentication. Impact is limited to confidentiality of adjacent memory and availability of the application process. Integrity is not affected by this specific defect.

No public proof-of-concept or in-the-wild exploitation has been reported for this CVE. See the Foxit Security Bulletins for technical details.

Detection Methods for CVE-2026-57258

Indicators of Compromise

Unexpected crashes of FoxitPDFEditor.exe or FoxitPDFReader.exe shortly after opening a PDF document
Windows Error Reporting (WER) entries or macOS crash reports referencing access violations in PRC or 3D parsing modules
PDF files containing embedded PRC streams received from untrusted email attachments, downloads, or shared drives

Detection Strategies

Hunt for process termination events on Foxit binaries correlated with recent PDF file open events
Inspect email and web gateways for PDF attachments containing PRC 3D annotations from untrusted senders
Review endpoint telemetry for repeated Foxit application crashes across multiple users, which may indicate a targeted campaign

Monitoring Recommendations

Collect and centralize application crash logs from Windows and macOS endpoints running Foxit products
Alert on Foxit process exits with non-zero status immediately following a PDF file handle open
Track Foxit software versions across the fleet to identify unpatched installations

How to Mitigate CVE-2026-57258

Immediate Actions Required

Inventory all endpoints running Foxit PDF Editor and Foxit PDF Reader on Windows and macOS
Apply the latest security update from Foxit as published in the vendor security bulletin
Restrict opening of PDF files received from untrusted external sources until patching is complete
Educate users on the risk of opening unsolicited PDF attachments containing 3D content

Patch Information

Foxit has published fixed builds through its security bulletin process. Refer to the Foxit Security Bulletins page for the specific fixed versions of Foxit PDF Editor and Foxit PDF Reader on Windows and macOS. Enable automatic updates within the Foxit application to ensure future fixes are received promptly.

Workarounds

Disable 3D content rendering in Foxit preferences to prevent PRC stream parsing
Configure email and web filtering to strip or quarantine PDFs containing embedded 3D annotations
Use protected view or an alternative sandboxed PDF viewer for documents from untrusted sources

bash

# Example: Windows registry key to disable 3D content in Foxit
# Consult Foxit documentation for the exact key for your installed version
reg add "HKCU\Software\Foxit Software\Foxit PDF Editor\Preferences\3D" /v bEnable3D /t REG_DWORD /d 0 /f