CVE-2026-25204: Samsung Escargot JavaScript DoS Vulnerability

CVE-2026-25204 Overview

CVE-2026-25204 is an insecure deserialization vulnerability discovered in Samsung's open-source Escargot JavaScript engine. The vulnerability allows an attacker to trigger a denial of service condition by causing a process abort through the deserialization of untrusted data. Escargot is a lightweight JavaScript engine designed for resource-constrained devices, making this vulnerability particularly impactful for IoT and embedded system deployments.

Critical Impact

Exploitation of this vulnerability can cause service disruption through process termination, affecting availability of applications and devices relying on the Escargot JavaScript engine.

Affected Products

• Samsung Escargot JavaScript Engine (versions prior to commit 97e8115ab1110bc502b4b5e4a0c689a71520d335)

Discovery Timeline

• 2026-04-13 - CVE-2026-25204 published to NVD
• 2026-04-13 - Last updated in NVD database

Technical Details for CVE-2026-25204

Vulnerability Analysis

This vulnerability is classified under CWE-502 (Deserialization of Untrusted Data). The flaw exists in the Escargot JavaScript engine's data deserialization routines, where malformed or maliciously crafted input can trigger an unexpected process abort.

The vulnerability requires local access to exploit, meaning an attacker needs to be able to provide input to an application using the Escargot engine. While no authentication is required to trigger the vulnerability, the attack does not compromise data confidentiality or integrity—it solely impacts system availability through a denial of service condition.

Root Cause

The root cause stems from insufficient validation of serialized data during the deserialization process. When the Escargot engine processes untrusted serialized input, it fails to properly validate the data structure or content before processing. This allows specially crafted input to trigger an unhandled exception or assertion failure, resulting in an immediate process abort.

Attack Vector

The attack vector is local, requiring an attacker to have the ability to provide malicious input to an application utilizing the Escargot JavaScript engine. Attack scenarios may include:

• Providing malicious JavaScript files to applications that use Escargot for script execution
• Manipulating serialized data streams that are processed by the engine
• Exploiting applications that accept untrusted user input and pass it to Escargot for processing

Since Escargot is designed for embedded and IoT devices, successful exploitation could disrupt critical device functionality, potentially requiring manual intervention to restore service.

Detection Methods for CVE-2026-25204

Indicators of Compromise

• Unexpected process termination or crash events in applications using the Escargot JavaScript engine
• Repeated service restarts or watchdog timer triggers on embedded devices
• Core dumps or crash logs indicating assertion failures in Escargot library functions
• Anomalous input patterns in application logs preceding service failures

Detection Strategies

• Monitor for abnormal process termination signals (SIGABRT, SIGSEGV) in Escargot-dependent applications
• Implement crash reporting and analysis for embedded devices running Escargot
• Deploy file integrity monitoring for JavaScript files processed by vulnerable applications
• Use application-level logging to track deserialization operations and detect anomalous patterns

Monitoring Recommendations

• Configure system monitoring to alert on repeated application crashes or restarts
• Implement centralized logging for IoT devices to capture crash events and correlate potential attack patterns
• Monitor resource utilization to detect potential DoS attack attempts targeting device availability

How to Mitigate CVE-2026-25204

Immediate Actions Required

• Update Samsung Escargot to commit 97e8115ab1110bc502b4b5e4a0c689a71520d335 or later
• Audit applications using Escargot to identify deployment locations and prioritize updates
• Implement input validation for any untrusted data passed to Escargot-based applications
• Consider isolating Escargot processes to limit the impact of potential crashes

Patch Information

Samsung has addressed this vulnerability in the Escargot GitHub repository. The fix is available in commit 97e8115ab1110bc502b4b5e4a0c689a71520d335. Organizations using Escargot should update to this commit or any subsequent release that includes this fix. For detailed patch information, refer to the GitHub Pull Request #1554.

Workarounds

• Restrict access to applications using Escargot to trusted users and inputs only
• Implement application-level sandboxing to contain the impact of process aborts
• Deploy process supervision and automatic restart mechanisms to minimize service disruption
• Validate and sanitize all external input before passing to Escargot for processing