CVE-2026-57257 Overview
CVE-2026-57257 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 exists in the Product Representation Compact (PRC) parsing logic. During PRC parsing, the application fails to validate the PRC entity index before accessing the entity array. A crafted PDF file containing a malformed PRC stream causes the reader to read outside the bounds of that array. The result is an application crash, producing a local denial-of-service condition against the user opening the document.
Critical Impact
An attacker who convinces a local user to open a malicious PDF can crash Foxit PDF Editor or Reader, disrupting document workflows on Windows and macOS endpoints.
Affected Products
- Foxit PDF Editor (Windows and macOS)
- Foxit PDF Reader (Windows and macOS)
- Deployments on Microsoft Windows and Apple macOS
Discovery Timeline
- 2026-07-08 - CVE-2026-57257 published to NVD
- 2026-07-09 - Last updated in NVD database
Technical Details for CVE-2026-57257
Vulnerability Analysis
The vulnerability resides in the PRC (Product Representation Compact) parser used by Foxit PDF Editor and Reader. PRC is an ISO-standardized format for embedding 3D CAD data inside PDF documents. During parsing, the code retrieves geometric and structural entities from an internal entity array using an index supplied by the PRC stream itself. The parser does not verify that this index falls within the allocated bounds of the array before dereferencing it.
When the index is attacker-controlled and exceeds the array size, the parser reads memory outside the intended buffer. This adjacent memory may not represent a valid entity object, causing subsequent field accesses to trigger an access violation or invalid pointer dereference. The process terminates, ending the user's PDF session.
Root Cause
The root cause is missing boundary verification on the PRC entity index prior to array lookup. The parser trusts the index value embedded in the PRC stream instead of comparing it against the current entity count. This pattern is a classic instance of [CWE-125] Out-of-Bounds Read, where untrusted input drives a memory access without a range check.
Attack Vector
Exploitation requires local user interaction. An attacker crafts a PDF containing a malformed PRC 3D annotation with an out-of-range entity index, then delivers it via email, file share, or web download. When the victim opens the document in an affected Foxit build, the parser dereferences the invalid index and the application crashes. The scope is limited to availability impact on the client process; no code execution or data disclosure is described in the advisory.
No verified proof-of-concept code is publicly available for this issue. Refer to the Foxit Security Bulletins for technical details as they are released.
Detection Methods for CVE-2026-57257
Indicators of Compromise
- Unexpected crashes of FoxitPDFEditor.exe or FoxitPDFReader.exe on Windows, or the equivalent macOS bundle, shortly after a user opens a PDF.
- Windows Application event log entries or macOS crash reports referencing access violations inside Foxit PRC-related modules.
- PDF files containing 3D annotations with PRC streams originating from untrusted external senders.
Detection Strategies
- Inspect inbound PDFs at the mail and web gateway for embedded 3D PRC streams and quarantine samples from untrusted sources.
- Correlate Foxit process termination events with the file open events that preceded them to isolate the triggering document.
- Hunt for repeated Foxit crash telemetry across multiple endpoints, which can indicate a targeted delivery campaign.
Monitoring Recommendations
- Forward Windows Application and Reliability logs, plus macOS ReportCrash output, to a central log platform for Foxit process failures.
- Track file provenance metadata (Mark-of-the-Web, quarantine attributes) on PDFs delivered to end users.
- Alert when the same PDF hash triggers Foxit crashes on more than one host.
How to Mitigate CVE-2026-57257
Immediate Actions Required
- Update Foxit PDF Editor and Foxit PDF Reader on all Windows and macOS endpoints to the fixed builds listed in the vendor advisory.
- Restrict opening of PDF files received from untrusted senders until patches are deployed.
- Educate users to report unexpected Foxit crashes rather than reopening the suspect file.
Patch Information
Foxit publishes fixed versions and remediation guidance through the Foxit Security Bulletins. Administrators should identify the specific bulletin covering CVE-2026-57257 and deploy the referenced updates through their standard software distribution channels.
Workarounds
- Disable 3D content rendering in Foxit preferences to prevent the PRC parser from processing embedded 3D annotations.
- Route inbound PDFs through a rendering or sanitization gateway that strips 3D annotations before delivery.
- Apply application allowlisting or attachment filtering to block PDFs from unverified external sources on affected systems.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
