CVE-2026-25205: Samsung Escargot Buffer Overflow Flaw

CVE-2026-25205 Overview

A heap-based buffer overflow vulnerability has been identified in Samsung's open source Escargot JavaScript engine. This vulnerability allows an attacker to perform out-of-bounds write operations, potentially leading to memory corruption and arbitrary code execution. The issue specifically affects commit hash 97e8115ab1110bc502b4b5e4a0c689a71520d335 of the Escargot project.

Critical Impact

Successful exploitation of this heap-based buffer overflow could allow an attacker to corrupt memory, potentially leading to arbitrary code execution or system compromise on devices utilizing the Escargot JavaScript engine.

Affected Products

• Samsung Escargot JavaScript Engine (commit 97e8115ab1110bc502b4b5e4a0c689a71520d335)

Discovery Timeline

• April 13, 2026 - CVE-2026-25205 published to NVD
• April 13, 2026 - Last updated in NVD database

Technical Details for CVE-2026-25205

Vulnerability Analysis

This vulnerability is classified as CWE-122: Heap-based Buffer Overflow. Heap-based buffer overflows occur when a program writes data beyond the boundaries of allocated heap memory. In the context of Escargot, a lightweight JavaScript engine designed for embedded systems and IoT devices, this type of vulnerability is particularly concerning as it could affect a wide range of Samsung products and third-party applications that integrate the engine.

The out-of-bounds write capability means that an attacker could potentially overwrite adjacent heap memory structures, including function pointers or other critical data. This creates opportunities for control flow hijacking and ultimately arbitrary code execution within the context of the vulnerable application.

Root Cause

The vulnerability stems from insufficient bounds checking during memory operations within the Escargot JavaScript engine. When processing certain inputs or executing specific JavaScript operations, the engine fails to properly validate buffer boundaries before writing data to heap-allocated memory. This allows write operations to exceed the allocated buffer size, corrupting adjacent memory regions.

Attack Vector

The attack vector for this vulnerability is local, requiring an attacker to have some level of access to the target system or the ability to provide malicious input to an application using the Escargot engine. Exploitation could occur through:

• Processing a maliciously crafted JavaScript file
• Executing attacker-controlled JavaScript code within an application embedding Escargot
• Providing specially crafted input to applications that use Escargot for JavaScript interpretation

While the attack complexity is high, requiring no privileges or user interaction, successful exploitation can lead to complete compromise of confidentiality, integrity, and availability of the affected system.

The vulnerability manifests in heap memory operations where boundary validation is insufficient. For technical implementation details and the specific code paths involved, see the GitHub Pull Request for Escargot.

Detection Methods for CVE-2026-25205

Indicators of Compromise

• Unexpected crashes or segmentation faults in applications using Escargot JavaScript engine
• Memory corruption errors or heap consistency check failures in process logs
• Abnormal memory allocation patterns or suspicious heap state modifications

Detection Strategies

• Deploy memory safety tools such as AddressSanitizer (ASan) during development and testing to detect heap overflow conditions
• Monitor applications using Escargot for unexpected behavior or crashes that may indicate exploitation attempts
• Implement file integrity monitoring for JavaScript files processed by Escargot-enabled applications
• Review application logs for patterns consistent with memory corruption exploits

Monitoring Recommendations

• Enable heap debugging features in development and staging environments to catch overflow conditions early
• Implement runtime application self-protection (RASP) solutions to detect memory corruption attempts
• Monitor system processes for signs of code injection or unexpected code execution paths
• Deploy SentinelOne Singularity Platform for real-time detection of exploitation attempts and memory corruption attacks

How to Mitigate CVE-2026-25205

Immediate Actions Required

• Identify all applications and systems utilizing the Escargot JavaScript engine at the vulnerable commit version
• Update Escargot to a patched version that addresses the heap-based buffer overflow
• Restrict access to systems running vulnerable versions of Escargot where possible
• Review and audit JavaScript inputs processed by Escargot-enabled applications

Patch Information

Samsung has addressed this vulnerability through a pull request to the Escargot repository. Organizations using Escargot should update to a version that includes the fix from GitHub Pull Request #1554. Ensure that the updated version is compiled and deployed to all affected systems.

Workarounds

• Restrict the execution of untrusted JavaScript code in applications using vulnerable versions of Escargot
• Implement input validation and sanitization for all JavaScript processed by Escargot
• Deploy application sandboxing to limit the impact of potential exploitation
• Consider using alternative JavaScript engines temporarily until the patch can be applied

# Update Escargot to patched version
git clone https://github.com/Samsung/escargot.git
cd escargot
git fetch origin pull/1554/head:fix-heap-overflow
git checkout fix-heap-overflow
# Rebuild and redeploy as per your build process