CVE-2025-66342: Canva Affinity RCE Vulnerability

CVE-2025-66342 Overview

A type confusion vulnerability exists in the EMF (Enhanced Metafile) functionality of Canva Affinity. This vulnerability occurs when the application improperly handles object types during the parsing of EMF files. A specially crafted EMF file can trigger this type confusion, leading to memory corruption and ultimately enabling arbitrary code execution on the affected system.

Critical Impact

Successful exploitation of this vulnerability allows attackers to execute arbitrary code in the context of the current user. If a user with administrative privileges opens a malicious EMF file, an attacker could gain complete control of the affected system.

Affected Products

• Canva Affinity for Windows (all versions prior to patched release)

Discovery Timeline

• 2026-03-17 - CVE-2025-66342 published to NVD
• 2026-03-19 - Last updated in NVD database

Technical Details for CVE-2025-66342

Vulnerability Analysis

This vulnerability is classified as CWE-843 (Access of Resource Using Incompatible Type), commonly known as type confusion. Type confusion vulnerabilities occur when a program allocates or initializes a resource such as a pointer, object, or variable using one type, but later accesses that resource using an incompatible type. In the context of Canva Affinity's EMF processing functionality, the application fails to properly validate or enforce type consistency when handling certain EMF record structures.

The vulnerability requires user interaction—specifically, a victim must open a maliciously crafted EMF file for exploitation to occur. This represents a local attack vector, meaning the attacker needs to deliver the malicious file to the victim through social engineering, email attachments, or other file-sharing mechanisms.

Root Cause

The root cause of CVE-2025-66342 lies in the improper type handling within the EMF parsing logic of Canva Affinity. When processing certain EMF record types, the application incorrectly interprets data structures, causing type confusion that corrupts memory. This occurs because the code assumes a specific type for an object or data structure without proper validation, leading to undefined behavior when the actual type differs from what was expected.

Attack Vector

The attack vector for this vulnerability requires local access and user interaction. An attacker must craft a malicious EMF file containing specially constructed record structures designed to trigger the type confusion condition. The attack flow typically follows this pattern:

1. Attacker creates a malicious EMF file with carefully crafted record structures
2. The malicious file is delivered to the victim (via email, download, or file share)
3. Victim opens the EMF file in Canva Affinity
4. The application's EMF parser processes the malformed records
5. Type confusion occurs, leading to memory corruption
6. Attacker achieves arbitrary code execution in the user's context

For detailed technical analysis of this vulnerability, refer to the Talos Intelligence Vulnerability Report.

Detection Methods for CVE-2025-66342

Indicators of Compromise

• Unexpected EMF files appearing in user directories or temp folders
• Canva Affinity application crashes when opening EMF files from untrusted sources
• Anomalous process behavior spawning from the Affinity application process
• Suspicious network connections initiated by Canva Affinity processes

Detection Strategies

• Monitor for unusual EMF file activity, particularly files from external or untrusted sources
• Implement endpoint detection rules to flag Canva Affinity processes spawning unexpected child processes
• Deploy file integrity monitoring on critical system directories
• Utilize behavioral analysis to detect memory corruption exploitation patterns

Monitoring Recommendations

• Enable verbose logging for Canva Affinity applications to capture file access events
• Configure SIEM rules to alert on EMF file downloads followed by application crashes
• Implement network monitoring to detect data exfiltration attempts following suspicious EMF file access
• Deploy endpoint telemetry to track process genealogy and command-line arguments

How to Mitigate CVE-2025-66342

Immediate Actions Required

• Apply vendor patches as soon as they become available from Canva
• Restrict users from opening EMF files from untrusted sources until patching is complete
• Implement email filtering to quarantine or scan EMF file attachments
• Educate users about the risks of opening files from unknown sources

Patch Information

Canva has released a security update addressing this vulnerability. Administrators should review the Canva Security Update for detailed patch information and update Canva Affinity to the latest available version that includes the security fix.

Workarounds

• Temporarily disable EMF file associations with Canva Affinity until patching is complete
• Use application whitelisting to prevent execution of untrusted files
• Configure email gateways to block or sandbox EMF attachments
• Implement network segmentation to limit the impact of potential exploitation

# Example: Block EMF file extensions at email gateway (configuration varies by product)
# Add .emf to blocked attachment types in your email security solution
# For Windows environments, consider Group Policy to disable EMF file associations
assoc .emf=