CVE-2026-40446: Samsung Escargot Type Confusion Vulnerability

CVE-2026-40446 Overview

A type confusion vulnerability (CWE-843) has been identified in Samsung Open Source Escargot, a lightweight JavaScript engine designed for IoT and embedded devices. The vulnerability allows for pointer manipulation through improper type handling, potentially enabling attackers to corrupt memory and execute arbitrary operations.

Critical Impact

This type confusion vulnerability in Escargot allows attackers to manipulate pointers through improper type handling, potentially leading to memory corruption, integrity violations, and denial of service conditions on affected systems.

Affected Products

• Samsung Open Source Escargot (commit 97e8115ab1110bc502b4b5e4a0c689a71520d335)

Discovery Timeline

• April 13, 2026 - CVE-2026-40446 published to NVD
• April 13, 2026 - Last updated in NVD database

Technical Details for CVE-2026-40446

Vulnerability Analysis

This vulnerability falls under CWE-843 (Access of Resource Using Incompatible Type), commonly known as type confusion. Type confusion occurs when a program allocates or initializes a resource such as a pointer, object, or variable using one type, but later accesses that resource using a type that is incompatible with the original type.

In the context of Samsung's Escargot JavaScript engine, the vulnerability manifests when the engine incorrectly interprets an object or value as a different type than intended. JavaScript engines are particularly susceptible to type confusion vulnerabilities due to their dynamic typing system and the need to perform rapid type conversions during script execution.

The attack requires local access to the target system, with high attack complexity indicating that specific conditions must be met for successful exploitation. While no authentication is required to trigger the vulnerability, the local attack vector limits the exposure to scenarios where an attacker already has some level of system access or can influence local script execution.

Root Cause

The root cause of this vulnerability lies in the improper validation of object types before accessing their underlying data structures. When the Escargot engine processes certain JavaScript constructs, it fails to properly verify that the type of an object matches the expected type before performing operations on its internal pointers or data.

This type mismatch allows an attacker to craft malicious JavaScript code that causes the engine to interpret data structures incorrectly, leading to pointer manipulation. The vulnerability affects the specific commit 97e8115ab1110bc502b4b5e4a0c689a71520d335 of the Escargot codebase.

Attack Vector

The attack vector for this vulnerability requires local access to the target system. An attacker would need to execute malicious JavaScript code within the Escargot engine environment. This could occur through:

1. Direct execution of malicious scripts on IoT or embedded devices running Escargot
2. Processing untrusted JavaScript content through applications using Escargot as their JavaScript engine
3. Supply chain attacks where malicious code is introduced into legitimate JavaScript applications

The vulnerability allows for pointer manipulation, which could enable an attacker to read or write arbitrary memory locations, potentially leading to information disclosure, code execution, or system crashes. Technical details regarding the specific exploitation mechanism can be found in the GitHub Pull Request that addresses this issue.

Detection Methods for CVE-2026-40446

Indicators of Compromise

• Unexpected crashes or segmentation faults in applications using Escargot JavaScript engine
• Abnormal memory access patterns or violations in Escargot-based applications
• Presence of JavaScript files containing unusual type coercion or object manipulation patterns
• System logs indicating memory corruption errors from Escargot processes

Detection Strategies

• Monitor for abnormal behavior in applications running the vulnerable Escargot commit (97e8115ab1110bc502b4b5e4a0c689a71520d335)
• Implement memory corruption detection tools (AddressSanitizer, Valgrind) during development and testing phases
• Deploy application-level monitoring to detect unusual JavaScript execution patterns
• Audit JavaScript inputs for potentially malicious type manipulation constructs

Monitoring Recommendations

• Enable verbose logging for Escargot-based applications to capture execution anomalies
• Implement crash reporting and analysis for embedded devices running Escargot
• Monitor system memory usage for unexpected allocation or access patterns
• Configure alerting for application crashes that may indicate exploitation attempts

How to Mitigate CVE-2026-40446

Immediate Actions Required

• Identify all systems and applications running Samsung Escargot JavaScript engine at the vulnerable commit
• Update Escargot to a patched version that incorporates the fix from Pull Request #1554
• Restrict local access to systems running Escargot to authorized users only
• Implement input validation for JavaScript content processed by Escargot-based applications

Patch Information

Samsung has addressed this vulnerability through Pull Request #1554 in the Escargot GitHub repository. Organizations should update their Escargot installations to a version that includes this fix. The patch adds proper type validation before accessing object internals, preventing the type confusion condition that enables pointer manipulation.

To apply the fix, update your Escargot installation to a commit that includes the merged pull request or build from the latest main branch that incorporates the security fix.

Workarounds

• Restrict execution of untrusted JavaScript code within Escargot environments
• Implement sandboxing for Escargot-based applications to limit the impact of potential exploitation
• Apply principle of least privilege to processes running the Escargot engine
• Consider using alternative JavaScript engines for security-critical applications until the patch can be applied