CVE-2026-25206: Escargot Information Disclosure Flaw

CVE-2026-25206 Overview

CVE-2026-25206 is an out-of-bounds read vulnerability discovered in Samsung's Open Source Escargot JavaScript engine. This memory corruption flaw allows attackers to trigger resource leak exposure by reading memory beyond allocated buffer boundaries. Escargot is a lightweight JavaScript engine used in embedded systems and IoT devices, making this vulnerability particularly concerning for resource-constrained environments.

Critical Impact

Successful exploitation of this out-of-bounds read vulnerability can lead to exposure of sensitive information from memory and potential denial of service conditions due to resource leaks.

Affected Products

• Samsung Open Source Escargot (commit 97e8115ab1110bc502b4b5e4a0c689a71520d335)

Discovery Timeline

• April 13, 2026 - CVE-2026-25206 published to NVD
• April 13, 2026 - Last updated in NVD database

Technical Details for CVE-2026-25206

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-bounds Read), a memory safety issue that occurs when software reads data past the end of an intended buffer. In the context of Escargot, this flaw can be triggered through specially crafted JavaScript code that causes the engine to access memory locations beyond allocated boundaries.

The vulnerability requires local access to exploit, with high attack complexity. While no privileges are required, successful exploitation can result in high confidentiality and availability impacts. The out-of-bounds read can expose sensitive information stored in adjacent memory regions and may cause application crashes leading to denial of service.

Root Cause

The root cause of CVE-2026-25206 lies in improper boundary checking within Escargot's memory handling routines. When processing certain JavaScript constructs, the engine fails to properly validate buffer boundaries before performing read operations, allowing access to memory outside the intended allocation. This type of vulnerability typically stems from missing or incorrect bounds validation logic in array or string handling code paths.

Attack Vector

The attack vector is local, meaning an attacker must have the ability to execute JavaScript code within the Escargot runtime environment. This could be achieved through:

1. Direct access to a system running Escargot
2. Providing malicious JavaScript input to an application embedding the Escargot engine
3. Exploiting other vulnerabilities to deliver malicious scripts to the JavaScript runtime

The vulnerability can be exploited by crafting JavaScript code that triggers the out-of-bounds read condition, potentially leaking memory contents or causing the application to crash. Technical details regarding the specific exploitation mechanism can be found in the GitHub Pull Request #1554 that addresses this issue.

Detection Methods for CVE-2026-25206

Indicators of Compromise

• Unexpected crashes or segmentation faults in applications using the Escargot JavaScript engine
• Memory access violations logged by the operating system or runtime environment
• Anomalous memory consumption patterns indicating potential resource leaks
• Application core dumps showing out-of-bounds memory access patterns

Detection Strategies

• Monitor application logs for memory-related errors and crashes in Escargot-powered applications
• Implement memory sanitizers (AddressSanitizer, Valgrind) during development and testing to detect out-of-bounds reads
• Deploy runtime application self-protection (RASP) solutions to detect memory corruption attempts
• Use static analysis tools to identify potentially vulnerable code patterns in JavaScript inputs

Monitoring Recommendations

• Enable verbose logging for applications embedding the Escargot engine to capture memory access errors
• Implement crash reporting mechanisms to track application stability and identify exploitation attempts
• Monitor system resource usage for signs of memory leaks or unusual consumption patterns
• Configure intrusion detection systems to alert on repeated application crashes that may indicate exploitation

How to Mitigate CVE-2026-25206

Immediate Actions Required

• Update Escargot to a version that includes the fix from Pull Request #1554
• Audit all applications and systems using the affected Escargot commit (97e8115ab1110bc502b4b5e4a0c689a71520d335)
• Restrict access to systems running vulnerable Escargot instances until patches are applied
• Implement input validation for any JavaScript code processed by the Escargot engine

Patch Information

Samsung has addressed this vulnerability through Pull Request #1554 in the Escargot GitHub repository. Organizations using Escargot should pull the latest commits from the official repository that include this fix. The patch corrects the boundary checking logic to prevent out-of-bounds read operations.

Workarounds

• Limit JavaScript execution to trusted code sources only until the patch can be applied
• Implement sandboxing or isolation for applications running the Escargot engine to contain potential exploitation
• Deploy memory protection mechanisms such as Address Space Layout Randomization (ASLR) to make exploitation more difficult
• Consider using alternative JavaScript engines if immediate patching is not feasible

# Update Escargot from the official repository
git clone https://github.com/Samsung/escargot.git
cd escargot
git pull origin master
# Rebuild the project following official build instructions