CVE-2026-57255: Foxit PDF Editor Buffer Overflow Flaw

CVE-2026-57255 Overview

CVE-2026-57255 affects Foxit PDF Reader and Foxit PDF Editor on Microsoft Windows. The vulnerability triggers when the application parses a PDF containing an abnormal color space whose attributes reference a semantically malformed function. Because the function's output is not validated, subsequent reads dereference an illegal pointer into an out-of-bounds memory region. The result is an application crash and potential exposure of adjacent memory contents. This flaw is classified under [CWE-125] (Out-of-Bounds Read) and requires local user interaction, typically opening a crafted PDF document.

Critical Impact
A crafted PDF can force Foxit PDF Reader and Editor to dereference an out-of-bounds pointer, crashing the application and disrupting document workflows on affected Windows endpoints.

Affected Products

Foxit PDF Editor (Windows)
Foxit PDF Reader (Windows)
Microsoft Windows (host operating system)

Discovery Timeline

2026-07-08 - CVE-2026-57255 published to NVD
2026-07-09 - Last updated in NVD database

Technical Details for CVE-2026-57255

Vulnerability Analysis

The vulnerability resides in how Foxit PDF Reader and Editor process color space objects embedded in PDF documents. PDF color spaces such as DeviceN or Separation accept a tint transformation function that maps input color components to output values. Foxit's parser accepts a function that is syntactically valid but semantically malformed, meaning its declared output range or sampling parameters do not match the values actually produced at runtime. When the rendering pipeline consumes those output values, it treats them as an index or pointer into a buffer without bounds checking. The unvalidated value causes the code to read memory outside the intended allocation. This produces a crash and denies service to the user opening the document.

Root Cause

The root cause is missing output validation on PDF function objects referenced by color space attributes. The parser trusts the function's declared behavior and skips runtime bounds checks on the derived pointer, which is the defining pattern of [CWE-125].

Attack Vector

Exploitation is local and requires user interaction. An attacker delivers a crafted PDF through email, a web download, or a shared file location. When a victim opens the file in Foxit PDF Reader or Editor on Windows, the malformed color space triggers the out-of-bounds read and crashes the process. The CVSS vector confirms local access with required user interaction and high availability impact but no integrity impact.

No public proof-of-concept exploit has been published, and the EPSS data indicates a low near-term exploitation probability. Verified technical code is not available for this issue; refer to the Foxit Security Bulletins for vendor-supplied details.

Detection Methods for CVE-2026-57255

Indicators of Compromise

Unexpected crashes of FoxitPDFReader.exe or FoxitPDFEditor.exe shortly after a user opens a PDF from email or a browser download.
Windows Error Reporting (WER) entries referencing access violations in Foxit rendering modules.
PDF files containing DeviceN or Separation color spaces with functions whose declared output range mismatches sampled data.

Detection Strategies

Inspect PDF attachments statically for color space dictionaries that reference FunctionType objects with inconsistent Range, Domain, or Size entries.
Correlate Foxit process crashes with recent PDF file opens using endpoint telemetry and parent-child process relationships.
Flag PDFs delivered from untrusted senders that contain unusually complex or nested color space definitions.

Monitoring Recommendations

Ingest Windows application crash events and Foxit-specific logs into a centralized analytics pipeline for pattern analysis.
Track file provenance for PDFs opened by end users, including originating URL, mail sender, and SHA-256 hash.
Alert on repeated Foxit crashes across multiple endpoints, which may indicate a targeted campaign distributing malformed PDFs.

How to Mitigate CVE-2026-57255

Immediate Actions Required

Apply the latest Foxit PDF Reader and Foxit PDF Editor updates as listed on the Foxit Security Bulletins page.
Restrict opening of PDFs received from untrusted or unverified sources until patched builds are deployed.
Enforce email gateway policies that scan or sandbox PDF attachments before delivery to end users.

Patch Information

Foxit publishes fixed versions and remediation guidance through its official advisory portal. Administrators should consult the Foxit Security Bulletins for the specific patched release addressing CVE-2026-57255 and deploy it across all Windows endpoints running Foxit PDF Reader or Editor.

Workarounds

Configure Foxit PDF Reader and Editor to open documents in a restricted or protected view mode where available.
Route PDF handling through a detonation sandbox or isolated browser for high-risk user groups.
Where feasible, disable automatic rendering of PDFs in mail clients and web browsers to require explicit user action.

bash

# Example: enumerate Foxit installations on Windows endpoints via PowerShell
Get-CimInstance -ClassName Win32_Product |
  Where-Object { $_.Name -like 'Foxit*PDF*' } |
  Select-Object Name, Version, InstallDate